Minolta XD-11 Assembly instructions

Minolta XD-11 Repair Guide
Figure IB
OVERRANGE LED
SHUTTER-SPEED
SCALE
UNDERRANGE LED
DIAPHRAGM WINDOW
Figure 3 Figure 4

SPEED
KNOB
DIAPHRAGM
COUPLING
X-SYNC
FLASHCORD
TERMINAL
LENS
LATCH
DEPTH-OF-FIELD
PREVIEW
Figure 1A
CAMERA CAPSULE
Type: 35mm e ectronica y contro ed
SLR with choice between aperture-
preferred or shutter-speed preferred
operation. E ectromagnetic reease. Fu
range of manua y ca ibrated shutter
speeds as we as automatic exposure
contro .
Meter: LED readout disp ays shutter
speed or f/stop which the camera wi
automatica y program. Si icon photo
diode, fu -aperture metering. Fi m-speed
range — ASA 12 to ASA 3200.
Battery: Two 1.5V si ver-oxide batteries
S-76, G-13, MS-76, or RS-76. Negative
ground. Battery compartment at bottom
of camera. Behavior without batteries —
shutter wi not re ease except at
mechanica speeds.
Shutter: Seiko MFC vertica y trave ing
meta foca -p ane shutter. E ectronic
shutter-speed contro at auto and manua
settings with two mechanica y contro ed
settings — bu b and 1/100 second. Trave
time — 6.0 to 6.9ms measured across a
20mm distance. Mechanica se f-timer.
Lens: Accepts a Mino ta MD enses.
F ange-foca distance 43.7mm (+0.02 —
0) measured from ens-mounting ring to
pressure-p ate rais.
Typical current draw with 3 supplied
to battery compartment: Meter — 8.5ma,
Shutter open — 17ma.
Circuit: Components are mounted on a
f exib e circuit board. You can rep ace in
dividua components or the comp ete
assemb y. Three ICs. Memory switch is at
top of camera, metering switch and
re ease switch are at back of front-p ate
assemb y (contro ed by reease button),
power switch is part of mirror-re ease
combination magnet. Two combination
magnets, one to re ease mirror and one to
contro diaphragm c osure. E ectro
magnet for shutter-speed contro , trigger
switch, and X-sync contacts are shutter
parts.
MINOLTA'S TRENDSETTER
The meteoric rise of the e ectronic,
super-compact SLRs forced many
camera manufacturers into a game of
catch-up. But Mino ta chose to set its
own standards with the XD-11. Among
other innovations, the XD-11 sett ed the
debate over aperture-preferred vs.
shutter-speed-preferred automation — it
gives you a choice between either mode.
To program the camera for automatic
shutter-speed contro , set the mode seec
tor to the "A" (aperture-preferred) position,
Fig. 2. A mechanica y contro ed shutter-
speed sca e now moves into the finder. Fig.
3. When you push the reease button part
way, a row of LEDs indicates the shutter
speed which the camera wi automatica y
seect. The appropriate LED ights a ongside
the shutter-speed ca ibration.
Triang e symbo s in the LED disp ay
show the range imitations. If the com
bination of ight eve and diaphragm
opening requires a shutter speed faster
than 1/1000 second, the overrange LED
turns on. The overrange LED indicates
that you're going to get an overexposure
un ess you se ect a sma er diaphragm
opening. If the underrange LED at the
bottom of the disp ay turns on, you're go
ing to get a shutter speed of 1 second or
s ower.
When you're using the "A " mode, you
can eave the speed knob at any of the
ca ibrated shutter speeds — 1 second
through 1/1000 second. The automatic
speed-contro circuit disregards the
speed-knob setting. As you se ect the
f/stop, a tab on the diaphragm-setting
ring rotates the camera's diaphragm-
metering ring. Fig. 1. The diaphragm-
metering ring moves a brush a ong a
resistance band, thereby programming
the f/stop information.
So far, the XD-11 sounds ike most of
the other e ectronic SLRs. But the XD-11
demonstrates its origina ity when you
se ect automatic diaphragm contro . Set
ting the mode se ector to "S " (shutter-
speed preferred) shifts the diaphragm
sca e into the finder, Fig. 4. Now the LED
disp ay indicates the diaphragm opening
which the camera wi automatica y pro
gram. A so notice in Fig. 4 that the
shutter-speed setting appears in the
finder. At the "A " mode. Fig. 3, a
mechanica y contro ed mask covers the
shutter-speed disp ay; the speed-knob
setting has no meaning in the aperture-
preferred mode.
For automatic diaphragm contro , turn
the diaphragm-setting ring to the sma est
f/stop. A tab on the diaphragm-setting

ring then comes against the minimum-
aperture ever, Fig. 1. As the tab pushes
the minimum-aperture ever from eft to
right, it programs the metering system for
the sma est f/stop of the particu ar ens.
On y the MD series of enses has the
minimum-aperture tab on the diaphragm-
setting ring. A though the ear ier MC
enses wi coup e to the diaphragm-
metering ring, they don't have the tab
which positions the minimum-aperture
ever. So, if you insta an MC ens on the
XD-11, the LED disp ay won't indicate an
automatica y programmed f/stop. You'
on y be ab e to turn on one LED — the
overrange LED.
You' a so get no diaphragm readout if
you forget to set the sma est f/stop on
the MD ens. The ca ibration for the
sma est f/stop has a green co or code.
Since an optica system ref ects the
se ected ca ibration into the finder, you
can quick y set the diaphragm for the "S "
mode. Simp y rotate the diaphragm-
setting ring unti the green number ap
pears in the finder, Fig. 4.
Now turn the speed knob to se ect the
shutter speed you want. As ong as the
LED disp ay indicates an f/stop in the
usab e diaphragm range, the camera
de ivers the shutter speed you've
se ected. It then imits how far the
diaphragm can c ose according to your
se ected shutter speed and to the ight
conditions.
Since the XD-11 a ready has shutter-
speed contro circuitry, it can go an extra
step to make sure you don't get an incor
rect exposure. Perhaps the camera can't
program the right f/stop for the particu ar
combination of ight eve and shutter
speed. A g ance at the LED readout te s
you to se ect a different shutter speed.
But, if you fai to make the necessary cor
rection, the camera's "computer" takes
over — it automatica y changes the shut
ter speed for you.
The camera ets you know when you're
going to get a shutter speed that's dif
ferent from the one you've se ected — it
turns on one of the range- imits LEDS as
you start depressing the reease button. If
the overrange LED turns on, you’ get an
exposure time that's faster than the speed-
knob setting. If the underrange LED turns
on, you' get an exposure time that's
s ower than the speed-knob setting.
To program the diaphragm opening,
the XD-11 contro s the movement of the
diaphragm-c osing ever, Fig. 5. The
diaphragm-c osing ever moves from right
to eft before the mirror swings to the tak
ing position. If the diaphragm-c osing
ever moves its fu distance, it a ows the
diaphragm to stop down to the sma est
f/stop. However, by imiting the move
ment of the diaphragm-c osing ever, the
XD-11 se ects other aperture sizes.
A combination magnet (permanent
magnet p us e ectromagnet) imits the
movement of the diaphragm-c osing
ever. As the diaphragm-c osing ever
starts to move, the permanent magnet
ho ds its armature. Then, when the
diaphragm reaches the proper opening
size, the circuit discharges a capacitor
through the coi that's wound around the
permanent-magnet core. The spurt of
current momentari y disab es the perma
nent magnet.
Now the armature of the combination
magnet jumps away from the core. And
the paw -shaped end of the armature
engages the ratchet teeth of a gear which
rotates as the diaphragm-c osing ever
moves. Stopping the rotation of the gear
a so stops the movement of the
diaphragm-c osing ever.
In turn, the diaphragm-c osing ever
stops the spring- oaded diaphragm from
c osing any further. At the other settings
of the mode se ector, the capacitor never
discharges through the coi of the com
bination magnet. As a resu t, the
diaphragm-c osing ever a ways moves its
fu distance. And the diaphragm stops
down to the f/stop you've se ected on the
diaphragm-setting ring.
The third setting of the mode se ector
— the "M " setting, Fig. 2 — provides
manua y ca ibrated shutter speeds. With
the mode se ector at "M ," the shutter
a ways de ivers the se ected shutter
speed. The LED disp ay now serves as a
cross-coup ed meter; it te s you what
shutter speed wi provide proper ex
posure according to the ight conditions
and to the diaphragm setting. A so, as
you turn the mode se ector from the "A "
position to the "M " position, the
viewfinder mask uncovers the shutter-
speed ca ibration in the finder, Fig. 4.
A though the speeds are manua y
se ected at the "M " mode, they're sti
e ectronica y contro ed. Consequent y,
a three functions depend on battery
power. In fact, even the shutter reease
requires battery power. A second com
bination magnet in the XD-11 re eases the
mirror when you push the reease button
far enough to c ose the reease switch.
The XD-11 uses two S-76 si ver-oxide
batteries housed at the bottom of the
camera. What if the batteries die? You'
then find that the shutter won't re ease.
But the XD-11 does provide two
mechanica settings — "B " and "0 ," Fig.
2. At the "B" setting, the shutter de ivers
a mechanica y contro ed bu b action. A
mechanica system then reeases the mir
ror. At the "0 " setting, the shutter
mechanica y de ivers the fastest fu -
aperture shutter speed — 1/100 second.
So, if the batteries die, you can turn the
speed knob to "0 " and continue using
the camera with e ectronic f ash.
The e ectronica y contro ed "X " set
ting a so provides the f ash speed of
1/100 second. However, the "X" setting
does depend on battery power — both
for the e ectromagnetic re ease and for
Figure 5 Figure 6 Front-plate/mirror-cage/shutter assembly

the e ectronica y timed exposure. You
can't use the "X " setting, the "B" set
ting, or the "0 " setting for automatic ex
posure contro . To he p prevent a possib e
operator error, the LED disp ay refuses to
indicate a shutter-speed or diaphragm
ca ibration at the "X ," "B," or "0 ” set
tings, Rather, the overrange LED a ways
turns on.
OTHER FEATURES OF THE XD-11
The XD-11 and its spinoff, the XD-5,
both use the Seiko MFC modu ar foca -
p ane shutter. With a modu ar foca -p ane
shutter, you might expect the XD-11 to
have a modu ar design. It does. But the
XD-11 is even more modu ar than most
cameras using simi ar shutters. You can
remove the front p ate, mirror cage, shutter,
and f ex circuit as one unit. Reaching the
shutter takes a minimum amount of time.
Practica y a of the e ectronic com
ponents mount to the f ex circuit. In many
cameras, the f ex circuit causes repair
prob ems; you must de icate y ift aside
portions of the f ex circuit to disassemb e
the camera. However, the XD-11 e imi
nates such prob ems. Since the f ex cir
cuit comes off with the front assemb y,
Fig. 6, there's itt e chance of damage.
As is typica , the f ex circuit covers the
pentaprism. Fortunate y, you don't have to
ift aside the f ex circuit to c ean the focus
ing screen. For that matter, you don't even
have to remove the top cover. To remove
the focusing screen, take out the two
screws that ho d the p ate at the top of the
mirror cage, Fig. 5. Lift out the cover p ate
and the focusing-screen retainer. You can
now drop out the focusing screen from in
side the mirror cage, Fig. 7.
Most of the remaining features are
pretty typica of modern SLRs. Notice
that the fi m-speed dia a ows you to set
intentiona overexposures or underex
posures, Fig. 2. When you se ect the fi m
speed, the fi m-speed dia rotates a brush
a ong the fi m-speed resistor. Moving the
compensation ever for intentiona over-
exposures or underexposures rotates the
entire fi m-speed resistor without moving
the brush.
The XD-11 a so accepts a power winder,
the Auto Winder A, and the Mino ta series
of dedicated f ash units. The 132X, 200X,
and 320X dedicated f ash units automatic
a y program the camera for the f ash
speed of 1/100 second. When the f ash
unit charges, the overrange LED f ashes on
and off in the finder.
CIRCUIT AT THE BOTTOM
OF THE XD-11
The battery-compartment cover screws
into the bottom p ate. So, once you
remove the bottom p ate, you can't power
the camera with its own batteries.
However, you can connect a 3V DC power
supp y to the battery compartment, Fig. 8.
Connect the positive power-supp y ead to
the battery-compartment termina and
connect the negative power-supp y ead to
ground (any meta part on the camera). A
the test vo tages we' be giving are
positive with respect to ground.
As you cock and reease the shutter,
notice the actions of the two evers at
tached to the transport cam — the mirror-
cocking ever and the shutter-cocking
ever, Fig. 9. The c ockwise rotation of
the transport cam drives the mirror-
cocking ever eft to right in Fig. 9. The
end of the mirror-cocking ever then
comes against the ro er on the mirror-
tensioning ever to charge the mirror. At
the same time, the transport cam draws
the shutter-cocking ever from eft to right
to charge the Seiko shutter.
The transport atch, Fig. 9, now drops
into engagement with a notch in the
transport cam. Consequent y, you can't
advance the wind ever a second time.
After the exposure, the mirror-tensioning
ever swings from right to eft, Fig. 9, and
strikes the transport-re ease ever. As the
transport-re ease ever rotates in a
c ockwise direction, it disengages the
transport atch from the transport cam.
A spring attached to the transport atch
and the transport-re ease ever provides
the switching contact for the power
winder. With the shutter re eased, the
power-winder switching contact moves
into the power-winder ocating bushing.
Fig. 9. The ocating bushing receives a pin
on the power winder. So, with the power
winder attached to the camera, the
power-winder switching contact touches
the pin.
The power-winder switching contact
now connects the power-winder pin to
ground. As a resu t, the power winder
goes into action; it advances the fi m and
cocks the shutter by rotating the power-
winder coup er, Fig. 9. When the shutter
reaches the cocked position, the trans
port atch drops into the notch in the
transport cam. The transport atch now
drives the power-winder switching con
tact away from the power-winder pin.
Since the power-winder pin no onger
connects to ground, the power winder
stops running.
At the other end of the camera, you
can see the circuit board which contains
the mirror-re ease and diaphragm-contro
components. Fig. 8. Locate the two capa
citors — C5 and C6. These are the capa-
IRANSPORT-
RELEASE
LEVER
MIRROR-COCKING
LEVER
LOCATING
BUSHING
LOOSE
DUST
SEAL
SHUTTER COCKING
LEVER
POWER-WINDER
SWITCHING
CONTACT
POWER-WINDER
COUPLER
TRANSPORT
CAM
POSITIVE BATTERY
Figure 8 Figure 9 Shutter Cocked

citors that discharge through the coi s of
the combination magnets. C6 discharges
through the coi of the mirror-re ease
combination magnet M1; C5 discharges
through the coi of the diaphragm-contro
combination magnet M2.
As yet, you can't reach the combina
tion magnets. So, if there's a prob em in
either the mirror-re ease circuit or in the
diaphragm-contro circuit, you may have
to remove the front-p ate assemb y.
However, you can troub eshoot both cir
cuits and pinpoint the ma function with
out further disassemb y. And, if you find
that the prob em is on the circuit board,
Fig. 8, you can make the repair without
disassemb ing the camera any further.
The two combination magnets have
very simi ar circuits. Fig. 10 shows the cir
cuit for the mirror-re ease magnet M1.
Transistor T6 serves as a switch between
the mirror-re ease capacitor C6 and the coi
of the mirror-re ease magnet M1. Turning
on T6 a ows the capacitor to discharge
through the coi . The spurt of current
causes the armature of M1 to jump away
from the core and reease the mirror.
You can see the M1 armature in Fig. 11.
A so ocate the mirror-re ease ever in the
same i ustration. When you push the
reease button, you shou d see the end of
the M1 armature move toward the front of
the camera and strike the mirror-re ease
ever.
Transistor T6 gets the re ease signa
from the comparator, Fig. 10. When the
re ease switch c oses, the contro circuit
sends a signa to the comparator. The
comparator then switches from a high
state to a ow state. The ow vo tage ap
p ied to the base of T6 turns on the tran
sistor. T6 now a ows the capacitor to
discharge through the coi of M1.
But notice in Fig. 10 that switch S1
must be c osed before the comparator
output connects to the base of T6. S1 sits
at the bottom of the camera, Fig. 11.
When you cock the shutter, S1 c oses to
connect the comparator to T6. S1 opens
after the exposure.
You can a so see the part that actuates
S1 in Fig. 11 — the ny on ug on the
transport-re ease ever. As the transport-
re ease ever swings in a c ockwise direc
tion, it a ows S1 to c ose. Then, when
the mirror-tensioning ever drives the
transport-re ease ever in a counter
c ockwise direction, the ny on ug pushes
the ong b ade of S1 away from the short
b ade.
S1 serves as a reset switch for the cir
cuit. But, if S1 fai s to c ose or makes
poor e ectrica contact, you' on y note
Figure 10
Figure 11
one ma function in the camera — the
shutter won't re ease. With S1 open,
transistor T6 never gets the ow-vo tage
signa from the comparator.
You can check S1 with a vo tmeter. At
the ong b ade of S1, Fig. 12, you shou d
measure 0V with the shutter in the reeased
position. You shou d measure around 2.5V
at the short bade, regardess of whether the
shutter is cocked or reeased. Since S1
shou d c ose when you cock the shutter,
you shou d a so measure around 2.5V at the
ong b ade. What if you measure 0V at the
ong b ade with the shutter cocked? Ap
parent y, S1 isn't c osing.
If you have to reform the b ades of SI,
check the timing. Cock the shutter and
ho d the wind ever fu y advanced. Then,
whi e measuring the vo tage at the ong
b ade of S1, a ow the wind ever to return
s ow y to its rest position. S1 shou d re
main open as the transport atch drops into
the first step in the transport cam, Fig. 9.
But S1 shou d c ose when the transport
atch drops into the second transport-cam
notch. So, as soon as the transport atch
drops into engagement with the second
notch, you shou d measure around 2.5V at
the ong b ade of S1. If the timing isn't cor
rect, reform the S1 b ades.

TROUBLESHOOTING THE
ELECTROMAGNETIC RELEASE
SYSTEM
If the shutter fai s to reease e ec-
tromagnetica y, you might first suspect
switch S1. But you can a so check the
other possibi ities after removing the bot
tom p ate. The mirror-re ease magnet M1
may have an open coi , the mirror-re ease
capacitor C6 may be open or shorted,
transistor T6 may be open, or T6 may not
be getting the reease signa from the
comparator.
It's a so possib e that the prob em is
mechanica rather than e ectronic. To
check the mechanica reease action, cock
the shutter and push the M1 armature.
Fig. 11, toward the front of the camera.
The mirror shou d reease. If it does, you
know the mechanica re ease is working
proper y. And the prob em must be with
the circuit.
Fig. 13 shows the approximate vo tages
you shou d measure across the M1 com
ponents. Notice that the mirror-re ease
capacitor C6 charges to the fu battery
vo tage. You shou d measure the +3V at
the positive termina of C6 regard ess of
whether the shutter is cocked or re eased.
However, before measuring vo tages,
you might try a quick shorting test to
simu taneous y check both capacitor C6
and the coi of magnet M1. Cock the
shutter. Then bypass transistor T6 by
shorting between its emitter and co ec
tor, Fig. 13. The mirror shou d re ease.
If your shorting test re eases the mirror,
you know that both the combination
magnet M1 and the mirror-re ease capa
citor C6 are good. You might next try
checking for the re ease signa at the base
of transistor T6, Fig. 13. Without de
pressing the reease button, you shou d
measure around 2.5V — the output of the
comparator in the "high" state. If you
measure the fu 3V signa , T6 apparent y
has a base-to-emitter short. Now depress
the reease button. The signa shou d
drop to around 1.3V.
If the circuit fai s to supp y the reease
signa to the base of T6, you' have to go
further in the disassemb y. There may be
a prob em with the reease switch or with
the re ease circuit. But if the transistor T6
is at fau t, you won't have to go any fur
ther. You can make a fina check on T6 by
shorting between the base and the co ec
tor, Fig. 13. Your short connects the base
to ground through the coi of M1. If the
transistor is good, the mirror shou d
reease.
Rep acing the transistor gives you a
choice in repair procedure. Mino ta does
supp y the individua components. But
you may prefer to rep ace the comp ete
circuit board (circuit base p ate B).
Now et's say that the shutter doesn't
re ease when you short between the emit
ter and co ector of T6. Either the com
bination magnet M1 or capacitor C6 cou d
be at fau t. But you might first suspect
the coi of M1. The red wire connected to
the co ector of T6 goes to one side of the
coi ; the other side of the coi connects to
ground through a b ack wire, Fig. 13. To
check the coi , measure the resistance
between the red coi wire and ground.
You shou d measure a very ow resistance
— around 15 ohms. If you measure no
continuity, you know that the combina
tion magnet M1 has an open coi . You'
then have to remove the front-p ate
assemb y to rep ace the combination
magnet.
CHECKING THE DIAPHRAGM-
CONTROL CIRCUIT
You can fo ow practica y the same
troub eshooting procedure to check the
circuit for the second combination
magnet — the diaphragm-contro magnet
M2. Remember, the diaphragm-contro
magnet arrests the diaphragm c osure in
the "S " mode. If there's a prob em in the
M2 contro circuit, the diaphragm a ways
stops down its fu amount.
In Fig. 14, note the simi arity between
the diaphragm-contro circuit and the
mirror-re ease circuit. When the dia
phragm reaches the proper f/stop, the
aperture-contro comparator switches on
transistor T13. T13 then supp ies the base
current which turns on transistor T5.
Turning on T5 a ows the diaphragm-
contro capacitor C5 to discharge through
the coi of the diaphragm-contro magnet
M2. M2 now repe s its armature to arrest
the diaphragm-c osing ever.
BLACK (GROUND)
RED TO
* BATTERY
Figure 13
Figure 14

WHITE TO S7
BLACK PURPLE
Figure 15
Figure 16
Figure 17
VIOLET
BROWN
TO M2
BLUE
The components for the diaphragm-
contro circuit a so mount to the circuit
board at the bottom of the camera, Fig. 15.
But you can't as yet see switch S7. Switch
S7 is part of the mirror-re ease-magnet
assemb y M1. As the armature of M1 jumps
away from the core to reease the mirror, it
opens S7. Notice in Fig. 14 that S7 must be
open in order for transistor T13 to conduct.
In effect, opening S7 turns on the
diaphragm-contro circuit. At the same
time, S7 provides power for the shutter
e ectromagnet (the e ectromagnet that
ho ds open the c osing b ade for the
ength of the exposure). Opening S7 a so
switches off the LED disp ay.
A prob em with S7, then, cou d cause
quite a few prob ems. A though you can't
as yet reach S7, you can check its opera
tion. Locate the white wire attached to
the ower circuit board, Fig. 15. Measure
the vo tage between the white wire and
ground; you shou d measure 0 vo t, in
dicating that S7 is c osed.
With S7 open, you shou d measure
around 1.3V at the white wire. But how
can you open S7 to measure the vo tage?
One way is to ho d open the shutter at the
bu b setting. Then push the M1 armature.
Fig. 16, away from the M1 core (toward
the front of the camera). The M1 ar
mature now opens switch S7. Conse
quent y, you shou d measure around 1,3V
at the white-wire connection, Fig. 15.
The technique for ho ding open switch
S7 a so a ows you to convenient y check
the coi of M2 and capacitor C5, Fig. 14.
Consider that the diaphragm-contro cir
cuit fai s to atch the diaphragm-c osing
ever; the diaphragm-c osing ever a ways
moves its fu distance in the "S" mode.
You might first check for the charge
across the diaphragm-contro capacitor
C5. Measure the vo tage between ground
and the positive C5 ead. Fig. 15; you
shou d measure -t-3V.
If you're getting the fu battery vo tage
across C5; the prob em cou d be with T5,
T13, or the coi of M2. Another possibi ity
is that T13 isn't getting the turn-on signa
from the aperture-contro comparator.
But you can quick y check the transistors
and the M2 coi with shorting tests.
There are a coup e of ways you can
check to see if M2 repes its armature
when C5 discharges. Try setting the mode
se ector to the "S" position. Then watch
the diaphragm-c osing ever, Fig. 5, as you
reease the shutter. If there's a prob em in
the diaphragm-contro circuit, the
diaphragm-c osing ever a ways trave s its
fu stroke.
Now short between the emitter and
co ector of transistor T5, Fig. 15, as you
re ease the shutter. The diaphragm-
c osing ever shou d stop after trave ing a

short distance. If it doesn't, you know
that the diaphragm-contro magnet M2
and the diaphragm-contro capacitor C5
are both doing their jobs.
But you may find that it's easier to check
the operation if you can actua y see the ar
mature of M2. Just pu aside the battery
compartment by removing its two screws,
Fig. 16. You can now see the M2 assemb y
through a c earance cutout in the bottom
of the body casting, Fig. 17.
To check M2, ho d open the shutter at
the bu b setting and disengage the M1 ar
mature as previous y described. Re
member, pushing the M1 armature away
from its core opens switch S7. S7 must be
open in order for transistor T13, Fig. 14, to
turn on.
Now short between the co ector and
the emitter of T5, Fig. 15. You shou d see
the armature jump toward the front of the
camera. If the armature jumps away from
the core, both M2 and C5 must be good.
You might then suspect transistors T5
and T13, Fig. 14. Whi e sti ho ding open
the shutter on bu b with S7 open, try
shorting between ground and the co ec
tor of T13, Fig. 15. Once again you shou d
see the M2 armature jump away from its
core. But, if the armature fai s to move,
transistor T5 must be defective.
If the armature does move, the prob em
may be with T13 or with the signa from
the aperture-contro comparator. You can
make one more shorting test to check
T13. Again ho d open the shutter on bu b
and open S7. Then short between the
base of T13 and ground. If the armature
jumps away from the core, there's no
prob em with T13. The prob em must be
in the aperture-contro circuit. You' have
to remove the top cover to reach the IC
that provides the turn-on signa .
Let's now consider the other possibi ity
— the M2 armature does not reease
when you short across transistor T5. You
might first suspect an open coi . To check
the coi continuity, measure the resis
tance between the brown wire, Fig. 15,
and ground. You shou d measure the
resistance of the coi — around 15 ohms.
A so suspect the diaphragm-contro
magnet M2 if the diaphragm fai s to stop
down. Such a ma function cou d indicate
a prob em either with the diaphragm-
contro magnet or with the circuit. But it's
usua y fair y easy to pinpoint the prob em
area — just check the operation at the dif
ferent modes. If the diaphragm fai s to
stop down at a three modes — A, M,
and S — suspect the diaphragm-contro
magnet M2. However, if the prob em on y
occurs at the S mode, suspect the circuit.
When the diaphragm fai s to stop
down, the diaphragm-contro magnet
isn’t ho ding its armature. The armature
then immediate y arrests the the
diaphragm-c osing ever. If the prob em
occurs at a three modes, try c eaning the
contact surfaces of the armature and of
the permanent magnet, Fig. 17. Dirt can
prevent the core from magnetica y ho d
ing the armature.
If c eaning doesn't do the job, the per
manent magnet may be defective. Try
pushing the armature of M2 away from
the core. Fig. 17; you shou d be ab e to
fee the magnetic attraction. A defective
permanent magnet requires that you
rep ace M2, a job which means pu ing the
front-p ate/mirror-cage assemb y.
Now consider the other possibi ity — the
prob em on y occurs at the S mode. The
symptom indicates that the diaphragm-
contro circuit gets the reease signa as
soon as switch S7 opens. You can spot the
prob em by using the technique we describ
ed earier at the bu b setting. Watch the ar
mature of M2 as you push the M1 armature
toward the front of the camera, Fig. 16. If
the M2 armature now jumps away from the
core, the circuit is sending the reease signa
right away.
To verify the ma function, you might
try operating the camera at the S mode
whi e you're shorting across the base and
emitter of transistor T13, Fig. 15. Your
short shou d keep transistor T13 shut off.
And, as a resu t, the armature of M2
shou d remain against the core. If the ar
mature sti jumps away from its core, the
prob em is on the circuit board at the bot
tom of the camera — most ike y, a
shorted transistor. But if the armature re
mains against the core, the prob em is in
the circuit that sends the signa to T13.
You must then remove the front-p ate/
mirror-cage assemb y. The prob em cou d
be as simp e as the vio et wire's shorting
to ground; or a switch or IC may be
defective.
SUMMARY OF TROUBLESHOOTING AT BOTTOM OF CAMERA
As you can see, it's possib e to check most of the e ectromagnetic diaphragm-
c osing and re ease systems from the bottom of the camera. What if the possi
bi ities we've discussed don't get you to the prob em? You' then have to go fur
ther. For examp e, if the mirror won't reease e ectromagnetica y, the prob em
cou d be in the reease switch. You can check the remaining switches just by
removing the top cover. The fo owing chart summarizes the troub eshooting
covered so far.
SYMPTOM
Shutter won't reease, LEDs do not
operate
POSSIBLE CAUSE
No battery power to ower circuit board
— check for 3V at red wire, Fig. 13. No
vo tage — check battery compart.
Shutter won't reease, LEDs operate
Diaphragm fai s to stop down, LEDs
operateA modes
S mode on y
Diaphragm a ways stops down fu y,
"over" LED remains on
Reease switch (remove top cover to
check)
Coi M1 open
Capacitor C6
Transistor T6
Switch SI, poor contact
So der connections to ower circuit
board (red, b ack, ye ow)
No re ease signa from comparator
Combination magnet M2, armature dirty
or permanent magnet defective
Vio et wire shorted to ground
Transistor T13
Comparator a ways presents reease
signa to T13
So der connections to ower circuit
board (purp e, white brown, back)
Fi m-speed resistor open (remove top
cover to check)

DIAPHRAGM
CONTROL
IC2 - SHUTTER-
RELEASE
LOCK
DRIVER
FOR LEDs
IC1 - DIAPHRAGM
CONTROL
PHOTOCELL
AMPLIFIER
SPEED
CONTROL
OUTPUT
LIGHT LEVEL + FILM SPEED
Figure 18 Actual schematic Figure 19

ACTUAL CIRCUIT FOR THE
COMBINATION MAGNETS
Fig. 18 shows the actua circuit for the
combination magnets M1 and M2. The
two IC's which drive the switching tran
sistors mount to the f ex circuit inside the
camera. Notice in Fig. 18 that a com
parator output of IC1 contro s the poten
tia on the emitter of T13; switch S7 con
nects to the T13 base (in the partia
schematics used ear ier for exp anation,
we showed the comparator contro ing
the base of T13).
With S7 c osed, the base of T13 con
nects to ground. Opening S7 then con
nects the base of T13 to a positive vo tage
— around 1.3V, measured at the white
wire, Fig. 18. T13 now has the vo tage it
needs at the base. However, the tran
sistor can't turn on unti the emitter
vo tage goes ess positive than the base
vo tage.
The comparator inside IC1, Fig. 18,
decides when it's time to turn on T13. IC1
actua y makes its exposure ca cu ation as
the diaphragm stops down. At the "S "
mode, IC1 compares the se ected shutter-
speed setting at one input with the ight
eve and the fi m-speed setting at the
other input. To stop the diaphragm at the
proper f/stop, the comparator inside IC1
switches ow. The emitter of T13 now
goes ess positive than the base. As a
resu t, T13 turns on and a ows C5 to
discharge through the coi of M2.
You can see how the comparator
makes its f/stop ca cu ation in Fig. 19.
The shutter-speed setting provides the in
put vo tage to one input of the com
parator; the combination of the fi m-
speed setting and the photoce output
provides the vo tage at the other input. If
input #1 in Fig. 19 is ess positive than in
put #2, the comparator output remains
high to keep T13 turned off.
However, as the diaphragm stops
down, the output of the photoce
decreases. The vo tage at input #2 then
goes ess positive. When the two inputs
see the same vo tage, the comparator
knows that the diaphragm has reached
the proper f/stop. Now the comparator
switches states — its output switches ow
and turns on T13.
Ear ier, we mentioned that S7 must
open before T13 can conduct. If S7 re
mains c osed, the base of T13 stays at
ground potentia . Remember, S7 opens
when the mirror-re ease combination
magnet M1 repe s its armature. Opening
S7 both app ies the base bias to T13 and
disconnects IC2 from ground.
IC2 serves as the driver for the LEDs.
So, when S7 breaks the IC2 ground con
nection, the viewfinder LEDs turn off.
A so, IC2 provides the shutter-re ease
ock for the mirror-re ease combination
magnet M1, Fig. 18. If the battery vo tage
drops too ow, the comparator inside IC2
won't switch on transistor T6. As a resu t,
the mirror-re ease combination magnet
can't re ease the mirror.
VARIATIONS IN THE LOWER
CIRCUIT BOARD
As mentioned previous y, the ower cir
cuit board. Fig. 20, comes as a comp ete
unit. A though we described techniques
for checking the individua components,
you can test the comp ete circuits with
one shot — just short the bases of the
contro transistors to ground.

Check the diaphragm-contro circuit by
ho ding open the shutter on bu b. Then
push the armature away from the core of
M1, Fig. 20, to open S7 Now short the base
of T13 (the violet or purple wire, Fig. 201 to
the camera body. You shou d see the ar
mature of M2 jump away from the core.
If shorting the vio et wire to ground
causes M2 to repe its armature, a of the
diaphragm-contro circuit on the bottom
of the camera must be working. What if
M2 doesn't repe its armature in norma
operation? Apparent y the comparator in
side IC1 isn’t switching ow to provide the
emitter bias for T13.
Simi ar y, you should be able to make
the mirror-release magnet M 1 repel its ar
mature by shorting the yellow wire to
ground (the ye ow wire that connects to
the base of T6, Fig. 20). Shorting the
ye ow wire to ground shou d turn on T6.
If M1 repe s its armature and re eases the
Figure 21 Early style board
mirror, the mirror-re ease components
must be good.
If you find that there's a prob em on the
ower circuit board, however, you may
run into a parts snag — there are two dif
ferent versions of the board, and the two
types won't a ways interchange. Fig. 21
shows the ear y version of the board; Fig.
22 shows the modified version.
Whether or not you can insta the ater
version in an ear ier camera depends on
the f ex circuit. You must then identify
the f ex circuit. A ternate y, you may have
to rep ace the comp ete f ex circuit and
the ower circuit board as a unit. You' be
ab e to identify the f ex circuit after you
remove the top cover.
REMOVING THE TOP COVER
Unscrew the wind- ever retaining
screw. Then disconnect the end of the
wind- ever return spring, Fig. 23, as you
ift off the wind ever. A so unscrew the
top-cover retaining ring around the wind
shaft. Fig. 24.
Next unscrew the retaining ring that
ho ds the speed knob. Fig. 24. A though
we used the bu b setting as a reference in
Fig. 24, the actua shutter-speed and fi m-
speed settings aren't important for
disassemb y. Remove the speed knob and
note the oose reease pin. The reease pin
c oses the switches for the metering and
re ease functions.
You can comp ete y remove the camera
back by depressing the hinge pin. Then
unscrew the rewind knob. Remove the
fi m-speed dia by unscrewing its retaining
ring and take out the parts indicated in
Fig. 25 — the detent p ate, the b ack
p astic decorator ring, the brass bushing,
and the exposure-compensation ever.
Fina y, remove the top-cover screws.
Two of the top-cover screws aso ho d the
diaphragm-window p ate, Fig. 26. If you
wish, you can remove the front decorator
p ate. Fig. 26, after you take off the
diaphragm-window p ate. However, uness
you know you're going to remove the front-
p ate/mirror-cage assemb y, you can eave
the front decorator p ate insta ed.
Before ifting off the top cover, push
down the eyepiece-b ind ever, Fig. 27.
The eyepiece b ind then covers the
eye ens. This precaution prevents the
other end of the eyepiece-b ind ever from
catching the f ex circuit as you ift off the
top cover.
REPLACING THE TOP COVER
When you rep ace the top cover, the
mode se ector, Fig. 24, must key to the
mode switch, Fig. 28. Fig. 28 shows the
mode switch set for manua shutter
speeds — the "M " position. To set
automatic shutter speeds, move the
mode switch to the center position; move
the mode switch a the way in a
counterc ockwise direction to set
automatic diaphragm openings.
Norma y, you' find that the mode
se ector keys most easi y at the "S" set
ting. Set the mode se ector in the top
cover to "S ." Then turn the mode switch.
Fig. 28, a the way in a counterc ockwise
direction. After seating the top cover,
check to see that the viewfinder sca e
switches from the diaphragm ca ibrations
to the shutter-speed ca ibrations when
you move the mode se ector to "A .”
A so, with the top cover removed, the
fi m-advance indicator, Fig. 28, tends to
sneak under the counter dia . Tightening
the retaining ring around the wind shaft.
Fig. 24, then binds both the counter dia
and the fi m-advance indicator.
The fi m-advance indicator on y moves
when there's fi m in the camera. As the
BLACK PURPLE OR VIOLET
Figure 22 Modified board

fi m winds onto the take-up spoo , it
pushes forward a ever inside the take-up
chamber. The ever then moves the fi m-
advance indicator from eft to right in Fig.
28. You can see the fi m-advance in
dicator through the window at the back
of the top cover.
Check the fi m-advance indicator after
you rep ace the retaining ring around the
wind shaft. Fig. 24. Reach to the front of
the take-up spoo and push forward the
ever that extends into the take-up
chamber; the fi m-advance indicator
shou d move into the window. If the fi m-
advance indicator doesn't move, oosen
the retaining ring. Fig. 24. Then ho d for
ward the ever inside the take-up chamber
so that you can see the fi m-advance in
dicator within its window. Continue
ho ding the ever as you tighten the re
taining ring.
To rep ace the wind ever, first hook its
ho e to the end of the wind- ever return
spring. Then rotate the wind ever in a
counterc ockwise direction as you seat it
over the wind shaft. The upper coi of the
wind ever return spring sometimes
sneaks under the wind ever. If that hap
pens, the wind ever won't return free y
after you rep ace the cover screw.
The fi m-speed dia can a so be tricky to
insta . Rep ace the exposure-compensation
ever and the detent rack as shown in Fig.
29; notice that the s ot in the exposure-
compensation ever fits over the tab on the
fi m-speed resistor ring. Then repace the
back p astic decorator ring. Fig. 25. The
notch in the decorator ring goes under the
exposure-compensation ever.
SPEED KNOB
RETAINING RING
TOP COVER
RETAINING RING
MODE SELECTOR
Figure 24
mmo
EXPOSURE COMPENSATION
LEVER / LONG TOP-COVER
SCREWS I
DETENT
PLATE FRONT-
DECORATOR
PLATE v
UPPER
BRASS
BUSHING
DECORATOR
RING
Figure 26
EYEPIECE-BLIND LEVER
TOP-COVER
SCREW -----
MODE SWITCH
IN M MODE A MODE
Figure

Figure 29
TAB ON
RESISTOR RING
SPRING ON
EXPOSURE-COMPENSATION
LEVER
Figure 31
Next seat the upper brass bushing. Fig.
25. Two tabs on the underside of the up
per brass bushing fit into the two s ots of
the ower brass bushing. Fig. 29. A so,
the ends of the spring attached to the
exposure-compensation ever, Fig. 29,
must come against the outer circum
ference of the upper brass bushing.
Fina y, seat the fi m-speed dia with its
s ot over the tab on the fi m-speed brush.
Fig. 30. Rep ace the b ack p ate (the p ate
with the compensation ca ibrations) so
that the fi m-speed window is over the
fi m-speed ca ibrations. Then rotate the
b ack p ate unti you fee its tab drop into
one of the s ots in the upper brass
bushing.
CHECKING THE FILM-SPEED
RESISTOR
With the top cover removed, you can
see the parts of the fi m-speed resistor.
Fig. 31. If you know you're going to
remove the front-p ate/mirror-cage
assemb y, ift out the fi m-speed ock, the
ower brass bushing, and the fi m-speed
brush. However, if you're troub e
shooting or adjusting the camera,
reassemb e the fi m-speed dia .
Why? With the fi m-speed dia remov
ed, the fi m-speed brush doesn't make
firm contact with the resistor ring, Fig.
31. The camera then exhibits the symp
toms of an open fi m-speed resistor:
- on y the overrange LED turns on
- the diaphragm a ways stops down
fu y in the S mode
-the shutter de ivers on y the
mechanica speed (1/1000 second) in
either automatic mode.
Even with the fi m-speed dia reas
semb ed, there's a trick to setting the fi m
speed. With the top cover removed,
neither the fi m-speed ock nor the
exposure-compensation ever keys to
anything. You must set both parts in their
proper positions before the fi m-speed
setting is va id.
A detent spring on the bottom of the
resistor ring provides the c ick stops for
the compensation settings. The detent
spring catches one of five detent s ots in
the rewind-shaft support p ate. Fig. 31.
First turn the exposure-compensation ever
unti the detent spring seats in the center
s ot; that's the "norma " position. The two
s ots on each side of the "norma " position
provide the intentiona overexposure and
underexposure settings.
Next rotate the fi m-speed ock to a ign
the "0" compensation ca ibration with
the index on the compensation ever. As
ong as the "0" ca ibration remains a ign-

ed, you can be ieve the fi m-speed set
ting. Natura y, Mino ta has a specia top
cover which ho ds the fi m-speed dia in
position for tests and adjustments (ASA
100, 0 compensation). But, without the
specia top cover, you' have to make
sure the parts don't shift out of position.
Fig. 32 i ustrates the operation of the
fi m-speed resistor. Setting the fi m speed
moves the fi m-speed brush a ong the
resistance band; changing the compensa
tion setting rotates the resistor ring. In
either case, you're changing the resis
tance between the b ue wire and the gray
wire to program the operationa amp ifier
inside IC1.
If you measure the resistance between
the purp e wire and the gray wire, Fig. 32,
you shou d read the va ue of the entire
resistance band — around 28K. Between
the b ue wire and the gray wire, you
shou d see the resistance smooth y
decrease as you set s ower fi m speeds;
the resistance shou d go from around 28K
to around 847 ohms. Here are the re
sistance va ues measured from a repre
sentative camera for different compensa
tion settings at ASA 100:
+ 1 5.84K
09.06K
-1 12.55K
CHECKING THE MODE SWITCH
Before rep acing the speed knob, you
might take a ook at the speed se ector
and the mode switch at the wind- ever
end of the camera. Fig. 33. At the "A ”
setting, the nut on the mode switch
comes against the mask ever. The nut
then pushes the mask ever in a c ockwise
direction. In turn, the mask ever pu s the
mask over the window for the shutter-
speed indication. Remember, the shutter-
speed setting has no meaning in the "A "
mode.
The spring- oaded sca e to the front of
the pentaprism provides the shutter-
speed indication. Fig. 34. A tungsten wire
coup es the shutter-speed sca e to the
speed se ector. Turning the speed se ec
tor in a counterc ockwise direction draws
the tungsten wire from eft to right in Fig.
34. The tungsten wire then pu s the
shutter-speed sca e to the faster-speed
ca ibrations. Notice that you can rotate
the wire-hooking nut. Fig. 33, to precise y
a ign the shutter-speed ca ibrations
through the finder.
Certain ma functions in the e ectronic
operation might ead you to suspect a
prob em with the mode switch. For exam
p e, suppose that there's poor brush con
tact or dirty contact surfaces. Poor con
tact at the eft-hand side of the brush.
Fig. 33, causes the overrange LED to re
main on. A so, the shutter de ivers on y its
mechanica speed. Poor contact at the
right-hand side causes the shutter to
hang open at a modes.
Later mode s of the camera have a sup
port arm above the mode switch; the sup
port arm maintains firm brush contact.
Figure 32
Figure 33
But, in ear ier mode s, the mode switch
shou d be one of your first suspects. You
can pinpoint a prob em to the mode
switch by using vo tage tests. However,
you might first rep ace the speed knob
and the wind ever. You’ then be ab e to
troub eshoot most of the e ectronics in
the camera — even though you can't as
yet reach a of the actua components.
Figure 34
PURPLE
FILM-SPEED BRUSH
^V W V W W V A
BLUE
GRAY

OPERATION OF THE METERING
SYSTEM
From the op of the camera, Fig. 34,
you can see on y one of the three IC's —
IC1. The other two IC's mount to the f ex
circuit at the side of the mirror cage. IC2,
as mentioned ear ier, contro s the
viewfinder LEDs. A hybrid IC — H-IC —
contains the transistor switching system
that inks together the various camera
functions.
But IC1 does just about everything ese
in the camera. For one thing, it contains
the op amp for the sing e si icon photo
diode (SPD), Fig. 35. Pushing the re ease
button part way c oses the metering
switch to supp y power to the circuit; you
shou d then measure +3V at pin 1 of IC1,
Fig. 34. A so, the circuit forward biases
the si icon photodiode.
Figure 35
Figure 36
Current through the SPD determines
the gate bias of an FET (fie d-effect tran
sistor), Fig. 36. You can't as yet see the
FET in the camera; it mounts to the
underside of the f ex circuit. The FET then
changes the inear current changes
through the SPD to inear vo tage
changes at the amp ifier input.
The vo tage at the output of the op
amp. Fig. 36, now goes more positive as
the ight intensity increases. This vo tage
output feeds two circuits — the memory
system through IC1 and the LED disp ay
through IC2. Besides seeing the output of
the op amp, IC2 receives an input from
the diaphragm resistor, Fig. 36. Conse
quent y, a three exposure variab es —
the ight eve , the fi m speed, and the
f/stop — contribute to the LED readout.
At the "S " mode, the minimum-aperture
information a so goes to IC2.
IC1 uses the op amp output to charge
the memory capacitor, Fig. 35. As the
output of the op amp goes more positive,
the vo tage measured across the memory
capacitor increases. So, if you connect a
vo tmeter across the memory capacitor,
you shou d get a higher reading as you in
crease the ight eve or set a faster fi m
speed. Just push the re ease button part
way to charge the memory capacitor.
The charge across the memory capa
citor can continue changing as ong as
the memory switch. Fig. 36, remains c os
ed. Fig. 33 points out the memory switch
in the camera. Just before the mirror
starts to rise, the insu ated ever shown in
Fig. 33 drives open the memory switch.
Opening the memory switch ocks in the
memory-capacitor charge.
However, you' notice in Fig. 36 that
the memory-capacitor charge doesn't
change with different diaphragm open
ings. The diaphragm resistor affects on y
the meter readout; it has nothing to say
about the actua exposure time. Yet the
exposure-contro circuit must know the
diaphragm setting in order to program the
proper shutter speed.
Un ike most systems, the XD-11 se ects
the automatic shutter speed by reading
the ight through a stopped-down aper
ture. With the diaphragm fu y open, the
SPD sees the maximum amount of ight.
The indication circuit for the LED readout
must know the se ected diaphragm open
ing in order to disp ay the proper shutter
speed at the "A " mode.
Then, when you push the re ease but
ton the rest of the way, the diaphragm
starts c osing. As a resu t, the SPD sees
ess and ess ight. Now the vo tage out
put of the op amp decreases (goes ess
positive) in proportion to the actua
diaphragm opening.
The vo tage across the memory
capacitor a so decreases as the dia
phragm stops down. Once the diaphragm
reaches the proper aperture size, the
memory switch opens. Consequent y, the
charge remains ocked in the memory
capacitor. The mem ory-capacitor
vo tage, modified by the decreasing out
put of the op amp, ref ects a of the ex
posure variab es — the ight eve, the
fi m-speed setting, and the diaphragm
opening.
After the memory switch opens, the
mirror starts moving to the taking posi
tion. The output of the op amp then
drops even more. But the actua metering
vo tage no onger matters — the memory
capacitor has a ready memorized the
reference vo tage.
The unique metering action can he p in
troub eshooting. Since the indication cir-
SPEED
COMPARATORS
FOR LEDS
—V ^ A A
DIAPHRAGM
RESISTOR
A AND S
MODES
(0
uj O
t o »
ir uj
= UiW
z a uj
to tone
MEMORY
SWITCH
MEMORY
CAPACITOR

cuit takes its ight reading through the
argest aperture — and the exposure-
contro circuit takes its ight reading
through the stopped-down aperture — the
two systems can disagree. For examp e,
suppose there’s a prob em with the
diaphragm resistor. A though the LED in
dication wou d then be incorrect, the shut
ter wou d sti provide the proper exposure.
You can get a better idea of the two
separate actions if you operate the
camera on "A " with the ens removed.
Try rotating the diaphragm-metering ring
unti the LED disp ay indicates a s ow
shutter speed. Then re ease the shutter.
You' find that the shutter de ivers an ex
posure time that's much faster than the
readout indicates. Why? You tricked the
readout into thinking you'd set a sma
aperture. But the exposure-contro circuit
knew better.
At the manua y ca ibrated settings, the
meter readout sti te s you the proper
shutter speed for the ight conditions.
However, the shutter-speed setting —
rather than the op amp — contro s the
vo tage across the memory capacitor. As
you set faster shutter speeds, the vo tage
across the memory capacitor increases.
Earier, we mentioned the symptom
when there's poor contact at one side of
the mode switch — the shutter hangs
open at a functions. You can see why in
Fig. 36. If the mode switch fai s to make
good contact, the memory capacitor
ycan't charge. Then, since the shutter
thinks you're shooting in tota darkness, it
hangs open.
A defective memory capacitor or poor
contact in the memory switch, Fig. 36,
resu ts in the same ma function. In fact,
any condition which prevents a reference
vo tage causes the shutter to hang open.
The b ock diagram of the shutter-speed
contro circuit, Fig. 37, may make the
reason apparent.
The memorized vo tage across the
memory capacitor provides the base bias
for the current-contro transistor, Fig. 37.
Current through the transistor charges
the timing capacitor. With a arger (more
positive) base vo tage, the transistor con
ducts harder; it then charges the timing
capacitor more quick y.
However, if there's no vo tage across
the memory capacitor, the transistor
won't conduct at a . As a resu t, the tim
ing capacitor never reaches the vo tage
which shuts off the e ectromagnet cur
rent. And the shutter stays open.
Fig. 37 a so shows the e ectromagnet
current path. Consider that you've just
comp eted the re ease-button stroke to
reease the shutter. As you've seen,
switch S7 remains c osed unti the mirror-
re ease combination magnet M2 repe s its
armature. With S7 c osed, the switching
transistor. Fig. 37, turns off; the base of
the transistor connects to ground.
With the switching transistor turned
off, OV appears at each ead of the e ec
tromagnet. Then, when the mirror re
eases, S7 opens and app ies a positive
vo tage to the transistor base. The swit
ching transistor now turns on, connec
ting the red e ectromagnet ead to + 3V.
The ho ding current f ows from the
e ectromagnet current source, Fig. 37,
through the coi , and through the tran
sistor to the positive side of the supp y.
Now the energized e ectromagnet ho ds
the c osing b ade to keep the shutter
open. The current source continues
feeding current to the e ectromagnet unti
the timing capacitor charges.
Figure 37
But the timing capacitor can t start
charging unti the trigger switch (timing
switch) opens. Fig. 37. As ong as the
trigger switch remains c osed, the
current-contro transistor won't conduct.
The trigger switch c oses when you cock
the shutter. Then, when the opening-
b ade assemb y starts to move, it opens
the trigger switch.
Now the expansion circuit feeds cur
rent to the emitter of the current-contro
transistor. Fig. 37. And the transistor
turns on, conducting the current that
charges the timing capacitor. The higher
the memorized reference vo tage, the
more quick y the timing capacitor reaches
the vo tage which shuts off the e ec
tromagnet current source.
Fig. 38 shows the vo tage measured
3V
Figure 38

across the timing capacitor. When you
push the re ease button far enough to
c ose the metering switch, a s ight vo tage
appears across the timing capacitor.
However, the timing capacitor can't
charge any further unti the trigger switch
opens. Opening the trigger switch then
a ows the timing capacitor to charge as
shown in Fig. 38. When the timing
capacitor reaches around 0.5V, it shuts
off the current through the e ectromagnet
to end the exposure.
You can't as yet reach most of the
components shown in Fig. 36 and Fig. 37.
But you can often pinpoint the prob em
from the top of the camera. So, before
covering the comp ete e ectronic opera
tion, et's run through the techniques you
can use to check the switches and the
e ectromagnet without disassemb y.
CHECKING THE ELECTROMAGNET
An open e ectromagnet coi causes the
shutter to de iver on y its mechanica
speed (1/1000 second or faster). A 
though you' have to remove the Seiko
shutter to rep ace the e ectromagnet, you
can check the coi without further dis
assemb y. Remove the sma section of in
su ating tape at the top of the f ex circuit.
You can now see the brown wire and the
red wire coming from the e ectromagnet.
Check the continuity of the coi by
measuring the resistance between the red
wire and the brown wire. You shou d
measure around 300 ohms. A ternate y,
you can perform a quick shorting test to
determine if the e ectromagnet is good.
Try shorting between the brown wire and
ground as you re ease the shutter. If the
coi is good, the shutter wi hang open
for as ong as you maintain the short.
With most e ectronic shutters, you can
check coi continuity by measuring the
vo tage at each e ectromagnet ead. If you
measure a vo tage at one ead but not at
the other, the coi must be open.
However, you've seen that the transistor
in series with the XD-11 e ectromagnet re
mains off unti you re ease the shutter.
So, at the red e ectromagnet ead, you'
measure 0V — not the fu battery vo tage
as you wou d with most other circuits.
You' a so measure 0V at the brown ead.
When you reease the shutter, the tran
sistor turns on and connects the red e ec
tromagnet ead to positive battery, Fig.
38. So, with the shutter open, you shou d
measure 3V at the red wire, Fig. 39. But
you shou d sti measure 0V at the brown
wire. The brown wire now connects to
0V, keeping a 3V potentia difference
across the e ectromagnet.
The vo tage at the brown wire switches
high to end the exposure. If you eave the
positive vo tmeter ead on the brown
wire, you can see the vo tage switch high.
You shou d see a vo tage indication at the
end of the exposure. But the vo tage on y
appears brief y. When the mirror returns,
switch S7, Fig. 38, once again opens to
shut off the transistor. Both e ec
tromagnet eads then return to 0V.
A poor ground connection in the circuit
may a so cause the shutter to de iver on y
its fastest speed. Suspect a poor ground
connection if you measure a vo tage at
the red e ectromagnet ead when you par
tia y depress the re ease button. If you
measure around 2.5V, try retouching the
so der connections to the b ack ground
wire, Fig. 39. However, you may have to
remove the front-p ate/m irror-cage
assemb y to correct the ground contact.
A screw on the section of f ex circuit that
mounts to the mirror cage makes the
ground connection through the camera
body.
If you measure the fu 3V to the red wire
and the brown wire, the switching tran
sistor may be shorted. Fig. 38. A 3V
reading cou d aso indicate a prob em with
the e ectromagnet current source. Both
components are inside H-IC, the hybrid IC
on the side of the mirror cage. You' have
to remove the front-p ate/mirror-cage
assemb y to rep ace the IC.
CHECKING THE METERING SWITCH
AND THE RELEASE SWITCH
Both the metering switch and the
re ease switch are at the back of the front-
p ate assemb y. As yet, you can't reach
the switches. But you can reach the
switch connections for troub eshooting.
The metering switch connects to the
green wire, and the reease switch con
nects to the orange wire, Fig. 39.
Fig. 40 shows the portion of the
schematic that inc udes the two switches.
As you start pushing the re ease button,
the metering switch S5 c oses. The
metering switch turns on transistor T1,
app ying the positive battery vo tage to
pin 1 of IC1 and to pin 2 of IC2.
Pushing the re ease button the rest of
the way c oses the re ease switch S3. The
re ease switch now te s the e ectro
magnetic re ease circuit to reease the
mirror. A so, the power-ho ding circuit —
transistor T11 in Fig. 40 — turns on. T11
now keeps transistor T1 conducting. So,
even if you a ow the reease button to
return, the circuit continues to operate.
Transistors T1 and T11 are both inside
H-IC on the side of the mirror cage. Diode
D2, a transistor connected as a diode.
Fig. 40, is a so inside the hybrid IC. You
might suspect a prob em in this portion of
the circuit if the camera draws power
constant y — even though you haven’t
depressed the re ease button.
What if the metering switch S5 fai s to
make contact? Obvious y, the LEDs wi
not turn on when you partia y depress the
reease button. Yet, thanks to the power-
ho ding circuit, the LEDs wi turn on when
you fu y depress the reease button. With
a defective reease switch S3, the shutter
won't re ease at the e ectronica y con
tro ed settings.
To check the metering switch, measure
the vo tage at the green wire, Fig. 39. You
shou d measure around 2.5V. When you
depress the reease button part way, you
shou d measure 0V at the green wire. If
the vo tage doesn't drop to 0V (ground),
the metering switch isn't making good
contact.
A ternate y, you can check the metering
switch by connecting an ohmmeter be
tween the green wire and ground; you
shou d measure direct continuity when
you push the reease button part way. Or
you can simp y short the green wire to
ground. Connecting the green wire direct y
Figure 39

to ground shou d turn on the LEDs.
If the LEDs turn on during your short
ing test, the prob em must be in the
metering switch. However, if the LEDs
sti won't turn on, the prob em is in the
circuit. Suppose, for examp e, that you
measure OV to pin 1 of IC1 whi e you're
shorting the green wire to ground.
Suspect a prob em with H-IC; transistor
T1, apparent y isn't turning on.
Use simi ar techniques to check the
reease switch. But remember — the
reease switch on y c oses at the e ec
tronica y contro ed speeds. Use any
speed-knob setting except bu b or the
mechanica 1/100 second. Then measure
the vo tage to the orange-wire connec
tion, Fig. 39. You shou d measure 2.5V
unti you fu y depress the re ease button;
the vo tage shou d drop to 0V with the
reease button depressed.
You can a so use a shorting test to check
the reease switch. Shorting the orange wire
to ground shou d reease the shutter. If your
shorting test doesn't reease the shutter, IC2
may be the prob em.
CHECKING THE TRIGGER SWITCH
Like the e ectromagnet, the trigger
switch is a shutter part. The trigger
switch shou d c ose when you cock the
shutter. When the shutter re eases, the
trigger switch shou d open to initiate the
exposure.
If the trigger switch remains c osed, the
shutter wi hang open. If the trigger
switch fai s to c ose or makes poor con
tact, you won't be ab e to bring in your
shutter-speed adjustments — especia y
the fast speeds. Erratic shutter speeds may
a so resu t from poor contact in the trigger
switch.
The trigger switch connects between
the b ack wire. Fig. 39, and ground. Check
the continuity between the b ack wire and
ground with the shutter cocked; you
shou d measure direct continuity, in
dicating that the trigger switch is c osed.
Then reease the shutter. You shou d now
measure no continuity — an open — be
tween the b ack wire and ground.
CHECKING THE MEMORY SWITCH
Poor contact in the memory switch nor
ma y causes the shutter to hang open.
With most cameras, you must perform
major surgery to reach the memory switch.
But, in the XD-11, you need on y remove
the top cover to c ean the memory switch
and check the continuity.
The b ade of the memory switch that's
c oser to the back of the camera connects
to the memory capacitor and to pin 10 of
IC1, Fig. 34. You can check the memory
switch by measuring the vo tage to pin 10
with the reease button partia y depress
ed; you shou d measure around 0.5V. If
the memory switch isn't making good
contact, you' measure 0V at pin 10.
Or you can measure the continuity be
tween the front b ade of the memory
switch, Fig. 33, and the memory ca
pacitor, Fig. 35. You shou d measure
direct continuity. With the shutter hed
open on bu b, you shou d measure no
continuity.
Figure 40

minolia :xe>ii
1- ■ — - ---- = ■■ === = ^= = = -
SCHEMATIC OF THE XD-11
It may at first appear that the comp ete schematic. Fig. 41,
shows on y two of the three IC's. However, the circ ed numbers
indicate the connections to the third IC — that’s H-IC, the
hybrid IC on the side of the mirror cage. A the parts enc osed
by the dotted ine are inside H-IC.
The schematic shows a the components inside H-IC. It a so
gives you a good indication as to the components inside the
other two IC's. Such detai ed information can be especia y
he pfu in troub eshooting. No, you can't take apart an IC to
repair the innards. But you can te what kinds of signa s shou d
appear at the IC pins.
For examp e, the arge triang e inside IC1 indicates the
amp ifier for the si icon photoce (SPC in the schematic). The
connection at pin 19 charges the memory capacitor C2. You
then know at a g ance that the vo tage at pin 19 shou d go more
positive as you increase the ight striking the SPC.
The center triang e inside IC1 is the comparator for the
diaphragm-contro circuit. When the output of the comparator
switches ow, it turns on transistor T13. T13 then switches on
T5. Now C5 discharges through the diaphragm-contro magnet
M2 to arrest the diaphragm c osure.
At pin 16 of IC1, another comparator provides the switch for
the c osing-curtain e ectromagnet M3. When the comparator
output at pin 16 drops ow, current f ows through M3 to ho d
open the shutter. The vo tage at pin 16 goes high to shut off the
e ectromagnet current.
Inside IC2, you can see the arge triang e which represents
the individua comparator stages for the LEDs. The cathode of
each LED connects to a comparator output. Notice that the
anodes of the LEDs connect to ■+ 3V when transistor T1 turns
on. Each LED then has the anode bias it needs to conduct. As
soon as the cathode of a particu ar LED switches ow, current
can f ow through that LED.
The sma comparator inside IC2 — the one connected to pin
3 — provides the reease ock. When the reease switch S3
c oses, the comparator compares the battery vo tage with a
reference vo tage. Then, providing there's sufficient power for
proper operation, the comparator switches ow. The ow
vo tage at pin 3 forward biases transistor T6 to re ease the mir
ror. Another triang e inside IC2 represents the ana og-to-digita
converter which ights the "60" LED when the f ash unit
charges.
As yet, you can on y reach one IC for vo tage tests — IC1 at
the top of the camera. However, you' be ab e to check H-IC
after you remove the front-p ate/mirror-cage assemb y. So,
before going through the rest of the e ectronic operation, we'
describe the procedure for separating the front-p ate/mirror-
cage assemb y from the body casting.

Figure 41