Akai AP-M77 User manual

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AUTOMATIC. PLAVER, AP-M77
FULL AUTOMATIC PLAYER.
move.
AP=M77

ABBREVIATIONS FOR SERVICE MANUAL
3 _ MODEL uy M77
ABBREVIATION | " EXPLANATION es . “| ae
AD3Just,
or
ADJustment
:
|
A.M
~.
Arm
Motor
BWD-
|.
BackWarD
;
.
We
ae)
CD:
Compact
Disc
|
|
DAD Digital Audio Disc
Dp ‘Decimal point —
FWD FoWarD
“H”
High
(Refferring
to
voltage)
‘
oe
ae
|
IPLS Instant Program Locating System
ies Low (Referring to voltage) ©
LED Light Emitting Diode
MI-COM MIcroCOMputer
MM. Main Motor
PCB fe Printed Circuit Board .
PTR ; Photo TRansistor
RPPS Random Program Play System
__ SENS SENSor, or SENSitivity
S.M
Slide
Motor
sw
SWitch
|
|
SYS-CON
SYStem
CONtrol
mere
ee
VR
:
'
-
Variable
Resistor
S

_—™
FULL AUTOMATIC PLAYER
wove. AP-M77
SECTION 1 SERVICE MANUAL .................... 3
SECTION
2
PARTS:
LIST
24230440033
02
can
Gow
s
cae
28

SAFETY
INSTRUCTIONS
OOO
SAFETY
CHECK
AFTER
SERVICING
Confirm
the
specified
insulation
resistance
between
power
cord
plug
prongs
and
externally
exposed
parts
of
the
set
is
greater
than
10
Mohms,
but
for
equipment
with
external
antenna
terminals
(tuner,
receiver,
etc.)
and
is
intended
for
or
[A],
specified
insulation
resistance
should
be
more
than
2.2
Mohms
(ground
terminals,
microphone
jacks,
headphone
jacks.
line-in-out
jacks
etc.)
PRECAUTIONS DURING SERVICING
1.
Parts
identified
by
the
A\
symbol
parts
are
critical
for
safety.
Replace
only
with
parts
number
specified.
2.
In
addition
to
safety,
other
parts
and
assemblies
are
specified
for
conformance
with
such
regulations
as
those
applying
to
spurious
radiation.
These
must
also
be
replaced
only
with
specified
replacements.
Examples:
RF
converters,
tuner
units,
antenna
selector
switches,
RF
cables,
noise
blocking
capacitors,
noise
blocking
filters,
etc.
3.
Use
specified
internal
wiring.
Note
especially:
1).
Wires
covered
with
PVC
tubing
‘2)
Double
insulated
wires
3).
High
voltage
leads
4.
Use
specified
insulating
materials
for
hazardous
live
parts.
Note
especially:
1)
“Insulation
Tape
2)
PVC
tubing
3)
Spacers
(Insulating
Barriers)
4)
Insulation
sheets
for
transistors
5)
Plastic
screws
for
fixing
microswitch
(especially
in
turntable)
oat
Pa
i
5.
When
replacing
AC
primary
side
components
(transformers,
power
cords,
noise
blocking
capacitors,
etc.),
wrap
ends
of
wires
securely
about
the
terminals
before
soldering.
ae
2 8 9
Observe
that
wires
do
not
contact
heat
producing
parts
(heatsinks,
oxide
metal
film
resistors,
fusible
resistors,
etc.).
Check
that
replaced
wires
do
not
contact
sharp
edged
or
pointed
parts.
Also
check
areas
surrounding
repaired
locations.
Use
care
that
foreign
objects
(screws,
solder
droplets,
etc.)
do
not
remain
inside
the
set.
VOLTAGE CONVERSION
Each
machine
is
preset
at
the
factory
according
to
its
destination,
but
some
machines
can
be
set
to
110V—120V
or
220V-—-240V
as
required.
If
your
machine’s
voltage
can
be
converted:
oO
le
Oo
Before
connecting
the
power
cord
or
assembling
the
melee
edb
iN
AC110-120V
platter,
turn
the
Voltage
Selector
located
on
the
top
of
SETTING
VOLTAGE
the
cabinet
with
a
screwdriver
until
the
correct
voltage
is
indicated.
Models
for
Japan,
USA,
Europe,
UK
and
Australia
are
not
equipped
with
this
facility.
NOTE:
Cycle
conversion
is
unnecessary
since
this
model
employs
DC
motors.
a

<2 RO
VII.
SECTION 1
SERVICE MANUAL
TABLE OF CONTENTS
SPECIFICATIONS . 0... 26 ice ete eet e nee e scene 4
DISMANTLING OF UNIT .. 0.0.0... 0. ccc eee eee 5
CONTROES 50555 esraiend eh ese Sens PS aE eh ac cca nels Geka oR Botan 6
PRINCIPAL PARTS LOCATION .............. 0.00000 cece eens 7
DESCRIPTION OF MISCELLANEOUS OPERATIONS .............. 9
5-1 OUTLINE OF AP-M77 FUNCTIONS................0000055 9
5-2 SPECIFICATION OF VARIOUS KEY OPERATIONS ........... 9
5-3. SPECIFICATION OF VARIOUS LEDS ...............0..... 12
54 SPECIFICATION OF COMMON BUS ...................05. 12
5-5 TIMING OF VARIOUS OPERATIONS ..............0..0005 13
ADJUSTMENTS: 20 oo oii G20 6001 wane Pare ge Sid lee aed inl Clee ae pce ie 19
6-1 ORDINARY MECHANICAL ADJUSTMENTS ................. 19
6-2 ELEVATION ARM POSITION ADJUSTMENT................. 19
6-3 POSITION SENSOR SENSITIVITY ADJUSTMENT ............ 20
6-4 OFF-SET VOLTAGE ADJUSTMENT...................0005 20
6-5 TRACKING SENSOR SENSITIVITY ADJUSTMENT ........... 21
6-6 MUSIC INTERVAL SENSOR SENSITIVITY ADJUSTMENT ...... 21
6-7 SPEED ADJUSTMENT.................. “dh gdh Mifesiungs Mace is once 21
6-8 LEAD-IN POSITION ADJUSTMENT ..........0.........000. 21
6-9 PLAY SW (SW902) POSITION ADJUSTMENT ............... 22
6-10 CLOSE CHASSIS (FOR CLOSE SW: SW2 on LIMIT PCB)
POSITION ADJUSTMENT....... 22
P.C BOARD TITLES AND IDENTIFICATION NUMBERS ........... 22
For basic adjustments, measuring methods, and operating principles, refer to GENERAL TECHNICAL
MANUAL.
SERVICE MANUAL AP-M77

1. SPECIFICATIONS
TURNTABLE (PLATTER)
Aluminum alloy diecast
DRIVE SYSTEM
Belt drive full automatic
MOTOR DC servo motor
SPEED 33-1/3 & 45 rpm
WOW & FLUTTER 0.04% (WRMS)
RUMBLE 70 dB (DIN-B)
TONEARM Linear tracking dynamic balanced type
EFFECTIVE ARM LENGTH 90 mm
ARM LIFTER Oil damped
OVER HANG 0mm
CARTRIDGE ; VM type
OUTPUT VOLTAGE 3.5mV
CHANNEL SEPARATION 20 dB
STYLUS RS-77
OPTIMAL STYLUS PRESSURE 1.25 g (Pre-adjusted)
POWER REQUIREMENTS
POWER CONSUMPTION
DIMENSIONS
WEIGHT
100V, 50/60 Hz for Japan
120V, 60 Hz for USA & Canada
220V, 50 Hz for Europe except UK
240V, 50 Hz for UK & Australia
110—120V/220—240V, 50/60 Hz switchable for other countries
15W (A, C, J, U Models)
350(W) x 115(H) x 250(D) mm
(13.8 x 4.5 x 9.8 inches)
6.7 kg (14.7 Ibs)
* For improvement purposes, specifications and design are subject to change without notice.
SERVICE MANUAL AP-M77

ee
iH. DISMANTLING OF UNIT
In
case
of
trouble,
etc.
necessitating
dismantling,
please
dismantle
in
the
order
shown
in
the
photographs.
Reassemble
in
reverse
order.
1
PULL ae All the adjustments can
' be accomplished within
MAIN MOTOR COVER the previous 5 steps.
UNPLUG FOUR CONNECTORS
UPPER CHASSIS BLOCK ON AUDIO PCB
STYLUS. CHANGE
PLATE
=]
Sa
PLATTER
DRIVE BELT
SCREWS
RUBBER SHEET
UNSCREW FROM
OTHERSIDE
BOTTOM
HOLDER
SCREWS
SCREWS
UPPER COVER
SCREWS es
‘SERVICE MANUAL AP-M77

ill. CONTROLS
® Fig. 3-1
RANOOM PROGRAM PLAY eYSTem
Ooo
ARM UFTER
Fig. 3-2
1. MAIN MOTOR COVER 9. ARM LIFTER BUTTON
2. CRANK DISK (RECORD SENSING PIN) uP (¥), DOWN (W)
3.
SPEED
33/AUTO/45
SELECTOR
10.
FWD
(<#4),
BWD
(be)
BUTTONS
4.
SENSOR
SENSITIVITY
LOW/MID/HIGH
SELECTOR
W/IPLS
FUNCTION
5.
STYLUS
CHANGE
PLATE
11.
POWER
ON/OFF
SWITCH
6.
DOOR
(CABINET)
OPEN/CLOSE
BUTTON
12.
PROGRAM
DISPLAY
7.
START
(<@)/CUT
(=m)
BUTTON
13.
INTRO
SCAN.
INDICATOR
8.
RANDOM
PROGRAM
PLAY
SYSTEM
BUTTONS
14.
SPEED
33/45
INDICATORS
INTRO SCAN, PROGRAM, CLEAR,
1~7 (PROGRAM)
SERVICE
MANUAL
AP-M77——————_____"-
eee

iV. PRINCIPAL PARTS LOCATION
= 9°90 8 NO aS & NUS
BELT (1.2 x D26)
ARM MOTOR MMN-5C2RG (M901)
REST PCB P1035A501L
SYNCHRO BELT
POSITION SENSOR (LED) PCB P1035A501G
LEAD-IN POSITION ADJUSTER
POSITION SENSOR (PTR) PCB P1035A501H
RELAY PCB P1035A501F
AUDIO PCB P1035A501B
STYLUS PRESSURE FINE-ADJUSTER
11.
12.
13.
14.
15.
16.
17.
SERVICE MANUAL AP-M77
uy
Fig.4-1 Top View
PLUNGER SOLENOID (SL901)
TRACKING PCB P1035A501P
PHOTO SENSOR (PH1)
FOR MUSIC INTERVAL DETECTION
SENSOR SENSITIVITY LOW/MID/HIGH
SELECTOR (SW1)
SPEED 45/AUTO/33 SELECTOR (SW2)
MAIN MOTOR BLOCK MMI-5P2R (M903)
REST POSITION SW (SW1)

wig hes eo PpowoenN>r Oo ©
FoS = >So) 7
POS OUR Ol a nN
L 1 ee.
(iy mm ap yc fay
IND PCB P1035A501M
PROGRAM IND PCB P1035A501K
MAIN MOTOR BLK (M903) MMI-5P2R
KEY BOARD (B) PCB P1035A501E
KEY BOARD (A) PCB P1035A5010
SLIDE PCB P1035A501N
SYSTEM CONTROL PCB P1035A501A
CLOSE Sw (sw2)
LIMIT PCB P1035A501J
OPEN sw (sw1)
AUDIO PCB P1035A501B
PLAY POSITION SW (SW902)
POWER SUPPLY PCB P1035A501C.
SYNCHRO BELT
15.
16.
17.
18.
19.
20.
SERVICE MANUAL AP-M77
Fig. 4-2 Inside View
POWER TRANS (7901)
APT-77-10 ([J] MODEL)
APT-77-20 ((a] MODEL)
APT-77-30 ([C] MODEL)
APT-77-40 ({E] MODEL)
APT-77-50 ([B] [S] MODELS)
APT-77-70 ({U] MODEL)
VOLTAGE SELECTOR (SW901)
MODEL ONLY
GEAR BLOCK
SLIDE MOTOR MMN-5C2R (M902)
WIND BELT
SLIDE MOTOR BELT

Sy?
5-1 OUTLINE OF AP-M77 FUNCTIONS
1) Electronic Type Full-Auto Player
Judges a disc record to be one of the three sizes,
30cm, 25cm, and 17cm (the size judgement
may therefore be disabled on occasions), leads in
accordance with the judged size, plays it, and
upon concluding the play, will lead out, again in
accordance with the size.
2) Direct Program Selection
Enables the programming of up to 7 pieces of
music for playing, and the storage of up to a
maximum of 15 pieces in the memory.
In selecting music pieces, rather than traversing the
entire record surface for search every time or
returning the arm to the arm rest each time a piece
has been played and searching for the next piece,
directly plays the target piece by traversing over
the shortest distance.
3) Skip & Dock
During the play of a record, when the FWD key
is pushed, will play either the spatially next piece
or the next programmed piece, and when the BWD
key is pushed, will play the current piece from its
beginning over again.
4) Common Bus Operated Synchro-Play & Auto-
Function When copying on a cassette deck, will
automatically perform such intelligent linkage
plays as having the deck make 4 seconds of an
unrecorded blank space, and just before the target
music piece begins, and then only, having the deck
phase out of the REC Pause and start recording.
As the player is started, the amplifier function will
automatically be switched to Phono, while when
conversely, other components operate and the
function is varied, will automatically cut the play
off.
5) Mode Confirmation by Attention Display
In the case of an anomalous or erroneous opera-
tion, or a particularly important behavior, will
draw the user’s attention to it with a 7-segment
LED display.
6) Fail-Safe
When an object operation fails to be performed for
long, or when this player has been started without
any record on the turntable, will automatically
disengage the mode.
7) Intro-Scan
After playing 8.4 seconds of a piece from the
beginning, will play 8.4 seconds of the beginning
of either the next piece or the next programmed
piece, and keep repeating this cycle.
SERVICE MANUAL AP-M77
V. DESCRIPTION OF MISCELLANEOUS OPERATIONS
8) Program Auto-Homing
When in a program mode, the FWD/BWD key is
pushed, the arm will traverse across and above the
record, and then when the key is released with the
arm midway above the record, will automatically
lead in to the beginning of a piece above which
the key has been released.
5-2 SPECIFICATION OF VARIOUS KEY
OPERATIONS
5-2-1 Start/Cut
1) When at Open Position
@ Will output “DISK” to the common bus, have the
main motor switched on, and 0.3 seconds later,
will have the door closed. By means of a record
sensing switch, when no record has been loaded,
will display ““E” and have the door opened. When
a record has been loaded, will have the door held
at the play position, and while detecting the
record size, will lead in to the target music piece.
2) When at Play Position
e@ When the arm is at the rest position, but no start
mode has been engaged, will output “DISK” to
the common bus, have the main motor switched
on, and 2 seconds later, have the arm forwarded.
When the record size has not been detected yet,
will lead in to the target piece of music while
detecting the size. When the size detection is
disabled, will display “E” and cut the play off.
Thereafter, even when the key is pushed again, will
only display “E” and refuse to acknowledge the
input. While the record size is being detected, a
7-segment LED will display “0” through “7”
sequentially, thereby indicating the size detection
in process.
When the arm is at other than its rest position, or
even at the rest position, will cut the play off if
a start mode has-been engaged. If an intro-scan or
program mode has been engaged, will disengage
the mode, turn the “intro”’ LED off, and have the
J-segment LED display “—”. If an arm-down
operation is in process, will have an arm-up opera-
tion performed and then have the arm returned to
the rest position.
3) When at Closed Position
@ Will display “E.” and acknowledge no command
inputs.
4) When at Any Other Position than1 ), 2), and3)
@ Will cut the play off if in a start mode. When in
any other mode, will only display “E.”’.

5-2-2 Open/Close
1) When at Open Position
@ Will have the main motor switched on, and 0.3
seconds later, have the door closed. By means of
the record sensing switch, will engage a stop mode
at the closed position if no record has been loaded,
or at the play position if a record has been loaded.
2) When at Play Position
@ Will have the play cut off, and after the arm
returns to the rest position, have the door opened.
Will also clear the record size and inter-piece data.
3) When at Closed Position .
@ Will have the play cut off, and then have the door
opened.
y) When at Any Other Position that1),2), and3)
Will have the door opened at any other position.
It is only when at the door open position that
closing operations will be performed, and at all
other times, when the key is pushed at the door
closed position to have an opening operation
performed, will have it opened, but when at the
_ door open position, will not have it closed.
@ Upon receiving the key input, an 8.4-second timer
will be activated, and if the designated position
is not reached within the time duration, “E.” will
be. displayed and the slide motor stopped. In addi-
tion, a similar timer will also be activated for
opening/closing operations during a start mode.
When the key is pushed for a second time, opening
operations will be phased into.
5-2-3. Power
1) This is a power-on/off switch that cyclically
operates to switch power on when it has been
off, or off when it has been on.
This key will be acknowledged regardless of a
multiple push or a follow-on push, and in any
mode.
2) At 2 seconds after power-on, will return the arm
to its rest position, and in the interim, will
acknowledge no other key than power. When the -
arm has been at its rest position from the begin-
ning, will acknowledge no other key for 2 seconds.
3) When at power-on, the door is at a position other
than prescribed, will have it opened. after the arm
has returned to its rest position.
5-2-4 Intro-Scan
1) Unless the mode is intro-scan and the size detec-
tion has been disabled, will have the “intro” LED
glow, and have the music introduction played for
8.4 seconda. Unless in a program mode, will store
i
[Current Music-Piece Number + 1] in the “intro”
memory. Only, if it is the 15th piece, no such
storage will be made.
2) When in an intro-scan mode, will turn the LED off
and disengage the intro-scan mode.
5-2-5 Forward
e@ Will acknowledge this key at the play position
only.
1) Prior to Size Detection
@ When this key is pushed, the arm will forward.
As soon as it leaves its rest position, the main
motor will be switched on, and “0” through “7”
displayed.
e As the arm reaches the 30 cm disc lead-in position,
the decimal point of the 7-segment LED will flash
on and off, and the arm will stop.
e@ When the key is released and pushed again, the
arm will forward again and the decimal point stop
flashing, until the 25 cm disc lead-in position is
reached where the arm will again stop.
Then, when the key is pushed one more time, the
arm will stop at the 17 cm disc lead-in position.
@ When the key is pushed still further and the arm
reaches the 17 cm disc lead-out position, the arm
will stop, and an “E.” display and a disabled
record size judgement will be effected together.
2) During Down Operations
e Will have an arm-up operation performed and if in
a full-auto mode, will skip to [Current Music-Piece
Number + 1]. Only, if the current piece is the
15th, will only have the arm-up operation per-
formed.
@ When in a program mode, programmed pieces still
remain stored in the memory, will skip to the next
programmed piece. When they are not stored, only
the arm will be lifted up.
3) During Up Operations
e If in a full-auto mode, will forward, even in an
intro-scan mode, as long as this key is held down.
Will, however, stop at the innermost circumference
dictated by the record size. When the key is
released, the arm will stop immediately.
e@ In a program mode, will forward similarly to the
full-auto mode as long as the key is held down, but
when it is released, will lead in to the beginning of
the then current piece of music. Since when the
piece is ended, the original program play will be
resumed, any music piece may be inserted at will.
However, only the beginnings of music pieces
having numbers 1 through 15 will be treated this
way.
SERVICE MANUAL AP-M77 ————__—___————- "ar

. :
5-2-6 Backward
Will acknowledge this key only at the play posi-
tion.
1) During Down Operations
Will have an arm-up operation performed, and lead
in to the beginning of the current music piece.
2) During Up Operations
If in a full-auto mode, will have the arm move
backward even in an intro-scan mode, as long as
this key is held down. However, upon return to
the rest position, the arm will stop, and the intro-
scan mode and program mode disengaged. When
the key is released, the arm will stop immediately.
In a program mode, while the key is held down,
will shift the arm backward in the same manner as
in a full-auto mode, but when the key is released,
will lead in to the beginning of the then current
piece of music.
Since when the piece is concluded, the original
program play will be resumed, any of the pieces of
music may be inserted at will. However, only the
beginning of music pieces having numbers 1
through 15 will be treated this way.
5-2-7 Cue
Will acknowledge this key at the play position
only.
1) Prior to Size Detection
Will acknowledge this key and have an arm-down
operation performed, only when the arm has been
forwarded with the forward key and stopped at
one of the various lead-in positions. As a result,
the record size having the lead-in position will
necessarily be confined to.
When at a point where the decimal point does not
flash on and off, will display “‘E.”.
2) Subsequent to Size Detection
Will acknowledge this key only within the record
playing range (from the lead-in position to the
lead-out position) that corresponds to individual
record sizes. Will, however, not acknowledge the
key when the arm is in motion, during arm-up
operations, in down servo modes, and in lead-in
awaiting modes.
During an arm-down operation, will have the arm
lifted up, and during an arm-up operation, will
have it lowered down. Ina full-auto mode but not
in intro-scan mode, will refuse to acknowledge this
key for 2 seconds after the plunger has been
switched off and the arm lifted up. In any other
mode, will refuse to acknowledge it for 4 seconds.
In a manual arm-down operation under the cue
key, will output “DISK” to the common bus, and
will disengage the muting mode and output
“Pause-Cancel”
to
the
common
bus
immediately
when
stylus
signals
are
present,
or
3
seconds
later
when
they
are
not.
-In
an
arm-up
operation,
will
exercise
muting
immediately,
and
0.3
seconds
later,
will
have
the
plunger
switched
off,
as
well
as
have
the
tracking
sensor
also
switched
off
another
0.3
seconds
thereafter.
When
lifting
the
arm
up
during
a
down
operation,
however,
will
immediately
have
the
plunger
and
tracking
sensor
switched
off.
In
either
case,
will
not
regard
the
arm
to
have
been
fully
lifted
until
2
seconds
later,
but
will
regard
the
up
operation
still
to
be
in
process.
Another
2
seconds
later,
will
output
“Play-Cancel”
to
the
common
bus.
5-2-8 Program-Clear
1) Nothing will happen except in program modes.
2)
In
a
program
mode,
will
cancel
the
program,
dis-
play
“—”,
disengage
the
program
mode,
and
phase
into
a
full-auto
mode.
When
during
a
start
mode,
will
lead
in,
or
when
searching
for
a
music
piece,
will
cut
the
play
off.
5-2-9 Program-Check
1) When in a program mode, programmed music-
piece numbers have been stored, will have the
7-segment LED turned off for 0.3 seconds, and
then
have
it
display
each
of
the
programmed
piece
numbers
in
the
stored
sequence
for
1
second
followed
by
0.3
seconds
of
a
display-off
period.
In this process, will not display numbers of the
music
pieces
whose
program
has
been
executed,
but
will
make
the
display
starting
with
the
number
of the music piece to be played next.
2) When this key is pushed during a program check-
ing process, will cancel the program check mode
and suspend any further display.
5-2-10 Program
1) Will acknowledge this key unless the record size
judgement has been disabled.
2) When keys 1 through 7 are pushed, will have the
depressed key number displayed for 1 second, and
engage
a
program
mode.
In
this
process,
the
decimal point in the 7-segment LED will also be
made to glow, and to keep on glowing until the
program mode is disengaged, unlike the 7 seg-
ments.
3) Numbers of up to 15 pieces of music may be
stored in the memory, and the music will be
played in the sequence of number inputs. When
the input of 16 or more numbers is attempted, will
display “F.” and indicate no further programming
capabilities.
4) As a programmed music piece is played, will clear
its number, creating room for one more number,
so that up to 15 pieces may be stored at all times.
SERVICE MANUAL AP-M77—————__——____———$—_————___
11

5-3
SPECIFICATION
OF
VARIOUS
LEDS"
5-3-1
“Intro”
LED
1)
Will
glow
when
the
intro-scan
key
is
pushed
and
an
intro-scan
mode
engaged.
2)
Will
go
out
when
in
an
intro-scan
mode,
this
key
has
been
pushed
and
the
mode
manually
dis-
”
engaged,
or
when
a
play
cut-off
operation
has
disengaged
the
mode.
5-3-2 7-Segment LED
1) Program Key Input Mode
©
Will
display
the
pushed
music
piece
number
for
one
second.
When
during
a
display,
a
program
key
is
pushed,
will
display
the
newly
pushed
piece
number for one second.
2) Attention Mode
@
Will
display
“E.”,
“—”,
or
“‘F.”
which
signify
Error,
Clear,
or
Full
respectively.
@
The
display
will
be
flashing
at
intervals
of
0.26
seconds,
and
go
on
flashing
for
2
seconds.
2 Program Check Mode
After
0.3
seconds
of
no
display,
will
display
a
music-piece
number
for
one
second,
and
then
another
0.3
seconds
of
no
display
will
follow.
When
a
balance
will
remains
of
the
program,
will
also display the remainder similarly.
4) Size Detection Mode
e
Will
display
“0.”
through
“7.”
in
program
modes,
r
“0”
through
“7”
in
all
other
modes,
sequen-
tially for 0.26 seconds each, and cyclically,
returning
to
“0”
after
“7”,
until
the
size
detection
is concluded.
5) When at Armrest Position
@
Will
display
“0.”
in
program
modes,
or
“0”
in
all
other modes.
6) Mute-On Mode
@
Will
flashingly
display
for
0.52
seconds
the
num-
ber
of
the
piece
of
music
that
is
beneath
the
stylus
on
the
record.
7) Mute-Off Mode
@
Will
steadily
display
the
number
of
the
piece
of
music
that
is
beneath
the
stylus
on
the
record.
5-4 SPECIFICATION OF COMMON BUS
5-4-1 Inputs
1) DISK-START
e@
Prior
to
the
size
detection,
the
arm
is
at
its
rest
position,
while
this
input
will
be
acknowledged
only
at
the
open
position
or
the
play
position
of
the
cabinet.
Thereafter,
similarly
to
normal
start
operations,
will
detect
the
size
and
lead
in.
@
Subsequent
to
the
size
detection,
will
not
ac-
knowledge
this
input
when
the
detection
has
been
disabled,
but
will
do
so
only
when
the
arm
has
just
been
lifted
up,
and
lead
in
to
the
first
music
piece
in
a
full-auto
mode,
or
to
the
target
piece
in
a
program
mode.
2) PHONO-REC
@ The same as DISK-START.
3) TUNER & TUNER-REC
@
The
arm
is
at
its
rest
position,
and
will
acknowl-
edge
this
input
only
during
a
start
operation.
Will
have
cut-off
operations
performed
in
all
other
cases.
Will
not
output
“REC-CANCEL”
into
the
common bus.
4) DAD & DAD-REC
e@ The same as TUNER.
5) DECK
@ The same as TUNER.
6) AUX
@ The same as TUNER.
7) Other Codes
@ Will refuse to acknowledge any other code.
8) Power-Off Mode
@ Will acknowledge codes 1) to 7) just for the first
time,
and
after
switching
power
on,
perform
the
operation corresponding to the code.
5-4-2 Outputs
1) DISK
© Will be output when the START/CUT key has
been pushed and a start mode manually engaged.
e@ Will be output when the arm lowers down.
2) PAUSE-CANCEL
@ Will be output when muting is disengaged.
3) PLAY-CANCEL
e@ Will be output 4 seconds after muting has been
turned on when the arm is lifted up by other than
a
cut-off
operation.
However,
when
the
arm
fails
to
return
to
the
armrest
or
the
play
has
been
cut
off
other
than
through
the
common
bus,
“STOP”
will be output, rather than “PLAY-CANCEL”, as
4 seconds have elapsed.
4) STOP
©
Will
be
output
4
seconds
after
muting
is
turned
on,
when
the
arm
has
been
lifted
up
by
a
cut-off
operation
and
other
than
through
the
common
bus.
However,
when
the
arm
fails
to
be
at
the
rest
position
or
the
cut-off
operation
is
no
longer
in
process,
“PLAY-CANCEL”
will
be
output,
rather
than
“STOP”.
—
a
SERVICE
MANUAL
APM
12

5-5 TIMING OF VARIOUS OPERATIONS
5-5-1 Lead-In
1) The arm will stop as it reaches a lead-in position.
If this is within 4 synchro seconds, will wait till
the 4 seconds elaspe, and then output “PLAY-
CANCEL”. If it is outside the 4 synchro seconds,
will not output “PLAY-CANCEL’ .
2) Will output “DISK” 0.6 seconds later, and have
the plunger switched on and the arm lowered
down.
3) For 0.3 seconds after the plunger has been
LEAD IN
V
ARM MOTOR
(FWD) ON OFF
\ \
|
|
switched on, will disregard stylus noises, and if
during the ensuing 0.7 seconds, stylus noises
emerge, will have the tracking sensor switched on.
4) If no stylus noises emerge during the 0.7 seconds,
will have the tracking sensor switched on, one
second thereafter.
5) At the end of 0.3 seconds after the tracking
sensor has been switched on, will output “PAUSE-
CANCEL”, and disengage muting.
ARM LIFTER
@) PLUNGER OFF 0.6 L ON
1
NEEDLE LANDING
“ uw
NOISE L
(4) TRACKING SENSOR OFF | ON
I
I
\
I |
!
I
N
{
(5) MUTE ON = fost OFF
{
) |
@
NEEDLE
LANDING
"L”
an
!
* |
(4) TRACKING SENSOR OFF |
ke— ISEC
|
? : !
(6) muTeE ON aj fesse 0.3SEC OFF
I
i
I
!
ec L3SEC =
t
Fig. 5-1
SERVICE MANUAL AP-M77

a
EE
SS
SSS
5-5-2 Music-Piece Interval Search Down
1)
As
the
target
music-piece
interval
is
reached,
the
during
the
ensuing
0.7
seconds,
stylus
noises
arm
will
stop.
If
it is
within
4
synchro
seconds,
emerge,
will
have
the
tracking
sensor
switched
on.
will
have
down
servo
exercised,
and
as
the
4)
If
no
stylus
noises
emerge
during
the
0.7
seconds,
4
seconds
have
elapsed,
will
output
“PLAY-
will
have
the
tracking
sensor
switched
on,
one
CANCEL”.
If
it
is
outside
the
4
synchro
seconds,
second
thereafter.
will
not
output
“PLAY-CANCEL”.
5)
For
0.3
seconds
after
the
tracking
sensor
has
been
2)
Will
then
exercise
another
second
of
down
servo,
switched
on,
will
disregard
audio
signals.
If
audio
and
output
“DISK”,
having
the
plunger
switched
signals
are
at
“L”
at
the
end
of
the
0.3
seconds,
on
and
the
arm
lowered
down.
Thereafter,
will
will
output
“PAUSE-CANCEL”
and
disengage
the
disengage
the
down
servo.
muting
mode.
If
audio
signals
are
at
“H”,
will
3)
For
0.3
seconds
after
the
plunger
has
been
continue
exercising
muting.
until
they
drop
down
switched
on,
will
disregard
stylus
nosies,
and
if
to
“L”.
MUSIC INTERVAL (BEGINNING)
ARM MOTOR y
(FWD)
Gd)
|
ON
OFF
|
\-SYNCHRO 48e¢.!
I
!
ARM DOWN | |
2)
ee
eavc
ON
are
OFF
@) ARM LIFTER
PLUNGER
(4) NEEDLE LANDING mon
NOISE
TRACKING
SENSOR
OFF
ON
() AUDIO SIGNAL
L L
1
O.3sec- te
: 1
(7)
MUTE
ON
!
OFF
|
{ nyt
vi
"i
1
AUDIO
SIGNAL
L
©
Z
t
I
es
ee
)
(@)
mute
ON
OFF
Fig. 5-2
SERVICE MANUAL APMI7? <_< —S— __
14

a
rr
5-5-3 Manual Arm-Down
1) When arm-down operations are possible, will
output “DISK”, and have the plunger switched on
and the arm lowered.
2) For 0.3 seconds after the plunger has been
switched on, will disregard stylus noises, and when
during the ensuing 0.7 seconds, stylus noises
emerge, will have the tracking sensor switched on
ARM DOWN START
\
and the muting mode disengaged.
3)
When
no
stylus
noises
emerge
during
the
0.7
seconds,
will
have
the
tracking
sensor
switched
on
one
second
later,
and
the
muting
mode
disengaged.
4)
When
disengaging
the
muting
mode,
will
output
“PAUSE-CANCEL”.
ARM LIFTER |
PLUNGER OFF ON
NEEDLE LANDING wou
NOISE
(3) TRACKING SENSOR
(4) MUTE
@) MUTE ON
Fig. 5-3
$= SERVICE MANUAL AP-M77 ————_ cme um
15

5-5-4
Aym-Up
1)
Will
exercise
muting.
2)
Will
have
the
plunger
switched
off
0.3
seconds
later,
and
the
arm
lifted
up.
3)
After
another
0.3
seconds,
will
have
the
tracking
sensor
switched
off.
4)
When
2
seconds
have
elapsed
since
the
muting
start,
will
judge
the
arm
lifting
to
have
been
MUTE
(1)
Mute
OFF
ARM
UP
START
iv
@
ARM
LIFTER
on
PLUNGER
5-5-5
Music-Piece
Interval
Detection
in
Play
Mode
1)
When
the
arm
has
been
fully
lowered,
will
detect
1.2
seconds
minimum
of
a
continuous
“L”
inter-
piece
signal.
2)
When
“L”
is
sustained
for
1.2
seconds,
will
detect
audio
signals,
and
when
they
become
“L”
at
a
point
removed
by
2.5
mm
(or
5
mm
if
the
current
MI-COM
PIN
a
ihe
ub
MUSIC
INTERVAL
SIGNAL
Ie
L.2sec
>
"H"
%
MUSIC
INTERVAL
SIGNAL
1.2SEC
zg
MI-COM
AUDIO
‘i
PIN @5) SIGNAL
X%
2.5mm JUDGE
—_—_—
1 |
ae
O.3SEC
1
concluded,
and
permit
the
arm
to
be
shifted
ai.
required.
5)
When
an
output
to
the
common
bus
is
required
will
provide
the
necessary
output
4
seconds
afte
the
muting
start
(either
“PLAY-CANCEL”
©
“STOP”’).
ON
OFF
OFF
ARM
UP
JUDGE
Fig. 5-4
piece
of
music
is
the
first
piece)
or
more
fm
the
beginning
of
the
current
piece
of
music,
gill
regard
it
to
be
a
music-piece
interval.
3)
If
the
point
is
not
removed
sufficiently
from
ihe
beginning
of
the
music
piece,
will
revert
to
dett-
ing
a
1.2-second
continuous
“L’’
inter-piece
sigtl.
LiMUSIC
INTERVI-
HiEXCEPT
MUSI¢
1
'
INTERVAL
——
|.2sec
>
Il
my
Py
1
1\.
L!NO
AUDIO
SIGNAL
H!AUDIO
SIGNAL
eee

aa,
5-5-6 Common Bus
1) When outputting, if the bus is busy, will not out-
put. If it is not busy, will output a leader section.
2) If after outputting the leader section, the bus is
again busy, it will mean a transmission from higher
level equipment, so that a signal receiving mode
will be engaged. If it is not busy, will output 8-bit
data after outputting a check section first.
3) For 100 msec after a data output, will inhibit any
further transmission.
4) In the case of reception, if the next data fails to
arrive within a predesignated length of time, will —
regard the reception to be ineffective. When data
to the last bit has been received, will refuse to be
engaged in further reception until the received
data has been decoded.
1) Serial Data Code
As shown in Fig. 5-7, the serial data code is com-
posed of the leader code, check code, and the data
code.
Leader Code: Selects operating equipment.
|
|
<
5-5-7 Common Bus System (Refer to Fig. 5-6)
For the network control of direct functions and
synchro-recording functions among the tuner, pre-
main amp, player, tape deck, CD player, and other
individual pieces of equipment, a common bus system
operated through serial data transfers has been
employed.
The individual components will be joined to a
common bus line with connectors in a two-wire
configuration of the signal and ground lines.
COMMON
BUS
ANALOGUE SIGNAL LINE
Check Code: Provides the check time to prevent
collisions of multiple simultaneous
signals.
Data Code: Operational Contents.
(1) (1) (1) (1) (0)(0) (1)
| |
| l
| LEADER CODE CHECK CODE ate hte 2p 3 4 ![ste6! 7 I
= Soap pe ec prey
| DA !
| i TA CODE ssl
I | |
lee 15.75 ms >< 9 to I8ms |
| I
lee: 24.75 to 33.75ms >
i}
Fig. 5-7
Q 1
1 I * Hol 1
min | | | min ae | |
0.4 Kee 0.4 Het 0.562540.1625
! | | (0.4 to 0.725)|
+0.75
+0 ;
1.12576 305 2.25 64
(0.8 to 1,125) (2.25 to 3.0)
Fig. 5-8
SERVICE MANUAL AP-M77

2) Allocations for Individual Codes
a.
Leader Code and Check Code
The individual equipment selecting leader code
selects
equipment
based
on
the
length
of
its
code
(Chart
1).
With
regard
to
the
check
code,
because
the total time for a leader code and a check
code put together has been set at 15.75 ms, the
remainder after deduction from 15.75 ms of the
leader code will be used for the check code.
[
|
Leader
Code
(ms)
|
Check
Code
(ms)
Timer
13.5
2.25
Player
12.375
3.375
DAD
(CD)
11.25
4.5
Cassette
Deck
9.0
6.75
Tuner
7.875
7.875
Pre-Main
Amp.
|
6.75
9.0
All code lengths will be made n x 1.125 ms.
Chart 1
The leader code with a wider pulse width always
shall carry a higher priority than that with a
narrower width.
. Data Code
For the operational contents of individual equip-
ment, their data shall be structured with combina-
tions of 8 bits, so that 82 kinds of operational
_ contents will be possible.
3) Data Transmission
a.
Upon receiving a key input, the individual com-
ponent shall check to assure the presence on the
common bus (hereinafter, bus) of no data from
other components before transmitting its data.
If any data is present there, not only shall the
transmission be called off, but the key input shall
also be made ineffective.
. When no data is: present on the bus, a prescribed
leader code shall be output.
. Upon concluding the output of a leader code, the
bus shall be lowered to ‘L’, and the signal status on
the bus checked again. If at that point, data is
present on the bus, a higher priority component
will have been outputting data, so that the trans-
mission shall be called off.
NOTES: 1.In the case of a key input requiring
data transmission, a key acknowledging
mode shall be engaged only after con-
firming in advance the feasibility of
sending the data.
2. An interval of 50 usec min. shall be pro-
vided after the lowering to ‘L’ before
checking the bus (Fig. 5-9).
d. After the prescribed length of a check code, the
es
8-bit data code section shall be output.
An interval of 100 msec min. shall be provided .
after a burst of transmission before transmitting
the next data.
4) Data Reception
a.
The component specified by the pulse of a leader
code section shall enter a receiving mode. Once the
receiving mode is engaged, control signals through
the bus shall take precedence, and key inputs shall
be inhibited. Even when the receiving mode has
been. engaged immediately after a key acknowl-
edgement, the key input shall be disregarded.
Even after a key input has been acknowledged and
its processing already started, or when bus data
arrives in the middle of a mechanism operation,
bus data shall still be acknowledged. Only, pro-
cessing of the bus data shall be executed after
conclusion of such ongoing operations. Accord-
ingly, the transmitting side shall not check for
the verification as to whether the data has been
received.
. An interval of 100 msec min. shall be provided
when transmitting data after receiving bus data.
. When transmission and reception have overlapped,
a receiving mode shall be engaged during the check
code section of the transmission, and sustained
thereafter.
. The leader code length shall be so selected for the
prevention of noise caused malfunctions that when
no signal arrives for a prescribed length of time
(20
to
40
msec),
the
receiving
mode
will
be
disengaged. A similar arrangement shall also be
made for the reading of code sections.
5) When the Timings for Transmission and Reception
Have Coincided with Each Other
When at the timing for an intended transmitting
operation, data has been sent out on the bus by
another component, the bus data shall be read,
and 100 msec later, the intended data transmitted.
However, when upon reading the data, the data
transmission is found to be no longer required, the
transmission shall be called off.
The 100 msec interval is required for these pur-
poses, and when processing of the data read or
equivalent requires more time than 100 msec, a
longer than 100 msec interval may also be pro-
vided.
SERVICE
MANUAL
AP-M77——————"_————~..
ees