AMSTRAD PC1512 User manual

I
PC1512
PERSONAL COMPUTER
PC-MM
MONOCHROME MONITOR
PC-CM
COLOUR MONITOR
SERVICE MANUAL

CONTENTS
Safety Note
Technical Specification
Servicing Note
FD-3 Flow Chart
FD-3 Flow Chart
FD-3 Servicing Information
FD-3 Exploded View
Cabinet Diagram Exploded View & Parts List
Electrical Parts List
Cabinet Diagram Exploded View
CPU P.C.B. Assembly Component Side
Exploded View CPU Unit
Hard Disc Installation Instructions
Alignment Instructions PC-CM
Alignment Instructions PC-MM/PC1512
Cabinet Diagram &Parts List PC-CM
Cabinet Diagram &Parts List PC-MM
Chassis Schematic Diagram
Keyboard Schematic Diagram &P.C.B. Layout
Keyboard Exploded View
Chassis Schematic Diagram PC-MM
Chassis Schematic Diagram
Chassis Schematic Diagram
Chassis Schematic Diagram PC-MM Monitor
Chassis Schematic Diagram
PC-CM Power Supply
PC-CM Main PCB Component Layout
PC-CM Main PCB Component Layout
CRT PC Board, Colour Monitor
Schematic Diagram FD-3 CPU
Page
2
2
3
3
4-6
7- 14
15
16& 17
18-20
21
22 &23
24
25
26
27
28
29
30-33
34&35
36
37
38
39
40
41
42
43
43
44
TECHNICAL SPECIFICATION
51 2K system unit with all circuitry on asingle motherboard.
8MHz 8086 processor.
Memory expandable on motherboard to 640K.
Integral colour graphics adaptor with special 16 colour hi-res
mode.
Three full-size compatible expansion slots with power available
in the standard unit to supply a hard disc and controller.
Choice of one or two 360K 51A" floppy discs or one floppy with a
1or 20 megabyte hard disc drive.
HARD DISC VERSIONS ARE SUPPLIED WITH AN EXTRA
FLOPPY DISC AND MANUAL WITH BACKUP, RESTORE AND
FORMAT UTILITIES.
Motherboard includes an RS232c serial and parallel interface
with standard connectors.
Loudspeaker with volume control.
Battery-backed real time clock and configuratioon RAM.
Socket for 8087 maths co-processor.
Connector for light pen.
Complete with Colour Monitor or Monochrome (Grey Level)
Monitor.
The standard built-in colour adaptor provides all the following
modes.
Medium resolution Alpha; 16 colours, 40x45 characters.
High resolution Alpha; 16 colours, 80x25 characters. .^
Medium resolution Graphics; 2colour, Three 4-colour pallettes,
320x200 pixels.
High resolution Graphics; 2colour, 640x200 pixels.
-FSpecial high-res Graphics; 16 colours, 640x200 pixels.
Full size QWERTY keyboard.
Illuminated Numlock and Capslock.
Keyboard joystock port.
Extra DEL-» and ENTER keys.
Two button Mouse with
Dedicated port on system unit.
Microsoft compatible MOUSE.COM plus special text operation.
DIMENSIONS (all in mm)
PC1 51 2SD System unit 372(w) x384(d) x135(h) 6.05Kg
PC1512DD System unit 372(w) x384(d) x135(h) 7.75Kg
Keyboard Unit inc feet 465(w) x160(d) x58(h) 1 .1 75Kg
PC-MM Monochrome Monitor 350(w) x300(d) x31 5(h) 7.43Kg
PC-CM Colour Monitor 372(w) x365(d) x330(h) 11.6Kg
SAFETY TEST
All monitors are safety tested to the following specifications.
1). Flash Test
Test at 3kV between the live and neutral of the mains lead joined together and
and ALL accessible metal points on the exterior of the set.
2). Insulation Resistance Test
Test between the live and neutral of the mains lead joined together and ALL
accessible metal points on the exterior of the set to show aresistance of at
least 4Mohm.
If after servicing there is any doubt about continued electrical safety the above
tests should be carried out.
AMSTRAD pic
BRENTWOOD HOUSE, 169 KINGS ROAD, BRENTWOOD, ESSEX CM14 4EF.
TELEPHONE; 0277 230222. TELEX: 995417 AMSELE G.

NOTE
THE FLOWCHARTS ARE FOR INFORMATION ONLY AND FOR WARRANTY PURPOSES ANY FAULTY
DRIVE MECHANISM MUST BE RETURNED TO AMSTRAD FOR REPLACEMENT. SERVICE AGENTS
SHOULD NOT ATTEMPT TO REPAIR THE MECHANISM.
SERVICE AGENTS SHOULD NOTE THAT THE HARD DISC UNITS ARE THE MOST SOPHISTICATED
MECHANISMS AND SHOULD NEVER BE OPENED IN ANORMAL ENVIRONMENT. IF ANY ATTEMPTS
ARE MADE TO OPEN THE HARD DISC UNITTHE GUARANTEE IS THEN INVALIDATED AND AMSTRAD
TAKES NO RESPONSIBILITY TO EXCHANGE THE DRIVE.
YOU SHOULD NOTE FURTHER THAT THERE ARE TWO TYPES OF HARD DISC UNITS IN USE
i.e. XEBEC AND TANDON. WHEN ORDERING THE REPLACEMENT UNITS MAKE SURE THAT THE
PART NO. IS EITHER 171663/X FOR XEBEC DRIVE OR 171663/T FOR TANDON DRIVE. THIS
INFORMATION APPLIES ONLY TO THE 20MB DRIVES.
AMSTRAD RESERVES THE RIGHT TO AMMEND THE CIRCUIT OR CHANGE THE COMPONENTS
WITHOUT PRIOR WARNING.
USE RP4 DIAGNOSTICS EXPANSION CARD OR DIAGNOSTIC DISC FOR FAULT FINDINGS.
FD-3 SERVICE INFORMATION
1. Introduction
This section is for the maintenance of DFC222A.
1-1 General
The floppy disk drive is ahigh precision equipment and requires the following jigs, tools, measuring
instruments, and adjustments when repairing or changing parts.
2. Special Jigs, Tools and Measuring Instruments
2-1 List of Special Jigs and Tools
CE diskette
Blank diskette
Test pin connector
Alignment adjusting jig
Otrack adjusting jig
2-2 List of Measuring Instruments
Oscilloscope
Brikon
Frequency counter
2-3 CE Diskette (Alignment Diskette)
This diskette is used for the following adjustments and inspection.
(1) R/W head radial position
(2) R/W head azimuth
(3) Index position

Trouble
3£
See error command
of FDC.
See this maintenance
maunal to other
mechanical troubles.
NO
YES ->-
Nn
YES ->- Change LED
V
Is write protect
signal received?
Medium may be
damaged. •-YES —
NO
Does it write if
medium is changed?
Y
NO
Cannot
write
YES-
\/
Is write
protect seal stuck
on medium?
NO
Y
YES
Write protect sensor has
failed. Check write
protect circuit and its
periphery.
J
Is head cord damaged
or disconnected?
V
NO
Remove seal
YES
Exchange head
Is write gate
correctly opened?
YES
_L_
Is setting
appropriate?
YES
NO
NO
Check circuit
check system
Drive NG
(stepping motor)
Check circuit

±
Is termination
resistor correctly
attached?
NO Mount
correctly
YES
1_
Is environment
condition appropriate? NO Set up environmental condition appropriately
YES
Are errors
caused after changing
to another medium?
NO Medium may
be faulty
YES
Is avery
large noise source
present?
YES Remove noise
source
NO
Is tlkere
&
Is there
sufficient head
head pressure
NO
NO Change head
YES
Are errors
caused on inner
circumference of
tracks?
NO
YES
Is spindle
speed OK? NO
YES
Is index
signal correctly sent? NO Adjustment
YES
\l/
Is azimuth
azimuth NO Tilting of guide shafts
due to shock, or heads
are defective
YES
Is seek
operation
normal?
NO >Check step motor and
driving mechanism
YES
Is time margin
of inner circumference
tracks sufficient?
YES
A
NO
YES
^_
^L
Change the printed
circuit board. Change
the head if problem
is not solved.
Is power NO Check power
ripple noise
correctly fed?
Check data separator
on system side
YES
v
Check circuit
(Read errors are caused)

FD-3 FLOWCHART
Are connectors
correctly plugged? NO .. Plug correctly
r> Medium may
be faulty
YES
NO ^
Is short bar
setting correctly?
Set normally
>
YES
YES
YES
sk_
Does it read
if changed to
another medium?
NO
Is alignment
OK?
YES
Is spindle
speed OK?
YES
1_
Is index signal
sent correctly?
YES
XL.
Is TRKOO OK?
YES
Is motor start
time appropriate?
YES
Is medium
rotating?
NO-
J1L.
Does cariage
operate properly? NO. Check step motor
and circuit head
driving mechanism
operating step
motor.
YES
Does read
waveform show
after adjustment?
YES Adjustment,
NO
NOi
V
NO
V
NO
Read circuit may
have problems.
Change MC3470AP.
Change printed
circuit board.
V
NO
V
Over-
speeding?
YES
Check motor
control printed
circuit board. Is
servo cord
disconnected
from motor?
V
Is index sent?
YES
Index sensor
is faulty
Adjust
NO
V
-NO
Change motor
alignment
3l
Read circuit has
aproblem.
Exchange
MC3470AP.
Change printer
circuit board.
XL.
Operating
normally?
Possibility of
or head cord
trouble.
Adjust
X-
Adjust
V
Can it be
adjusted?
V
NO
NO
XL
Is power fed? NO Check power
YES
A
Does DC motor
operate?
(Apply 12V)
NO^ Change DC motor *
YES
J/ NO^
Are cords
and wires correctly
connected?
Correct
incorrect wiring.
YES
-YES
IOK Is motor ON
signal sent? NO. Check signal on
system side
YES
*_
Possibility of circuit
part faults. Adjust
centering motor-control
printed circuit board.
W
-YES- OK
Drive has problem
(Medium slip or
other reason).

3. Diagnosis Procedure
3-1 General
Errors caused by an incorrect operating procedure, erroneous programming, damaged diskette,
and sott errors caused by dirty air, random electric noise, and other external factors are often
considered to be drive failures or incorrect adjustments. Check that errors are repetitively
produced with the first diskette and that similar errors are also produced with other diskettes,
unless obvious assembly trouble and damage are found in visual inspection.
3-2 Soft Error Detection and Correction
Soft errors are generally caused by the following.
(1) Dirty air between the R/W head and disk. Normally, this dirt is cleaned by the liner in the diskette.
(2) Random electrical noise less than several microseconds.
(3) Delicate track misalignment and writing timing misalignment that are not detected during
writing may cause soft errors during reading.
(4) Improper ground of the drive or host system power supply.
(5) Improper motor speed.
The following actions are required on the control side to recover the foregoing soft errors.
(1) Reread the track ten times or until data recovers.
(2) Access the head to an adjacent track in the same direction as the track if the error is not
recovered by Step 1. Then return the head to the previous track.
(3) Repeat Step 1.
(4) Errors that cannot be recovered after taking these steps cannot be recovered.
3-3 Write Error
Operate READ-AFTER-WRITE if an error occurs during the write operation.
If the error cannot be recovered after operating READ-AFTER-WRITE more than four times,
operate READ-AFTER-WRITE on another track to determine whether the diskette or drive is
responsible for the error. Change the diskette and repeat these steps if the same error remains. If
the error still remains, the drive has some fault and if the error is erased, the diskette is defective
and should be discarded.
3-4 Read Error
Most errors are soft errors. Data can be recovered by following the error recovery steps (3-2).
3-5 Seek Error
(1) Trouble with the stepping motor or stepping motor drive circuit.
(2) Carriage trouble.
Seek error is recovered by system soft. There are two recovering ways.
(1) Recalibrate
(2) Detect ID field
3-6 Compatibility Error
In some cases, data written by one drive cannot be read by another drive. This is dur mainly to the
following reasons:
The check points are listed below.
(1) Improper head alignment —5-2
(2) The head output is low —5-6
(3) Motor speed irregularity —5-1
(4) Check if the recommended sector format is set up.
3-7 List of Test Points (see figure 3-7)
Test Point Signal Name
TP1 AMP OUT +
TP2 AMP OUT-
TP3 GND
TP4 STEP
TP5 READ DATA
TP6 INDEX
TP7 WRITE PROTECT
TP8 TRACK
TP9 GND
3
Fig. 3-7 Test Point Layout

4. Parts Exchange
4-1 Printed Circuit Board Exchange (See Figure 4-1)
4-1-1 Printed Circuit Board Removal
a) Expand the two shield board pins and cord holder pin.
b) Unfasten the three fix screws and remove the shield board.
c) Disconnect the connectors (head, stepping motor, spindle motor, track sensor, index sensor, and
write protect sensor).
d) Unfasten the three printed circuit board fix screws.
e) Moves '.he head to inner about 10mm.
f) Lift the rear edge of the printed circuit board and pull it back.
4-1-2 Printed Circuit Board Mounting and Adjustment
a) Tilt the printed circuit board as if to lower the front edge, insert the front LED into the LED
insertion hole on the front plate, then lower the rear edge.
b) Fix the printed circuit board with three screws.
c) Secure the shield board with three fix screws.
d) Reconnect the disconnected connectors (head, stepping motor, spindle motor, track sensor,
index sensor, and write protect sensor).
e) Bend the two shield board pins and fix the head cable.
f) Check the spindle speed (5-1), radial track (5-2), track sensor (5-3), azimuth (5-4), index burst
time (5-5), level (5-6), resolution (5-7), symmetry (5-8) and write protect sensor (5-9) after mounting.
Note: Insert the head cord under the shield board and fix at the same routing as before exchange.
Fig. 4-1 Printed Circuit Board Removal
4-2 Lever Exchange (See Figure 4-2)
4-2-1 Lever Removal
a) Set the lever horizontally.
b) Unfasten the fix screw of the lever.
c) Pull the lever forward.
4-2-2 Lever Mounting
a) Place the wide part of the lever cam on the hub side and check that the lever shaft hole can be
seen from above. (Hub open state).
b) Set the lever horizontally and insert from the front.
c) Secure the lever with ascrew.
4-3 Front Plate Exchange (See Figure 4-3).
4-3-1 Front Plate Removal
a) Remove the lever as described in 4-2-1.
b) Unfasten the two front plate fix screws.
c) Pull the front plate forward. ^
4-3-2 Front Plate Mounting
a) Insert the front plate from the front.
b) Secure the front plate with two screws.
Mount the lever as described in 4-2-2.
4-4 Eject Assembly Exchange (See Figure 4-4)
4-4-1 Eject Assembly Removal.
a) Make the lever vertical (clamp state).
b) Remove the printed circuit board as described in 4-1-1.
c) Insert protection paper (high quality white paper approximately 10x30 mm) between the heads
to protect them.
d) Unfasten the two Eject Assembly fix screws.
e) Lift the top head (approximately 2-3mm), and remove the Eject Assembly.
4-4-2 Eject Assembly Mounting and Adjustment.
a) Lift the top head and insert the Eject Assembly under the Head Arm.
b) Adjust the position of eject assembly that the ejector lock when the diskette is inserted and the
diskette is ejected when the lever is operated and secure the eject assembly with two screws.
c) Remove the protection paper.
d) Mount the printed circuit board as described in 4-1-2.
8

Ilj^
4-5 Lever Frame Assembly Exchange (See Figure 4-5)
4-5-1 Lever Frame Assembly Removal
a) Remove the printed circuit board as described in 4-1-1.
b) Remove the lever as described in 4-2-1.
c) Remove the front plate as described in 4-3-1
.
d) Remove the eject assembly as described in 4-4-1.
e) Unfasten the four lever frame assembly fix screws.
f) Lift the lever frame assembly slightly making sure that the top head is not raised, and remove the
slidinh to the left.
4-5-2 Lever Frame Assembly Jvlounting and Adjustment.
a) Lift the top head slightly and slide the pad mounting part of the lever frame assembly under the
top head.
b) Secure the lever frame assembly with four screws.
c) Mount the eject assembly as described in 4-4-2.
d) Mount the front plate as described in 4-3-2.
e) Mount the lever as described in 4-2-2.
f) Unfasten the two screws of hub shaft holder and centre by moving the hub up and down several
times and secure the two screws.
g) Mount the printed circuit board ad described in 4-1-2.
h) After mounting, adjust the index burst time. (Refer to 5-5).
4-6 Stepping Motor Assembly Exchange (See Figure 4-6)
4-6-1 Stepping Motor Assembly Removal
a) Remove the printed circuit board as described in 4-1-1.
b) Unfasten the head assembly metal belt fix screw.
c) Unfasten the stepping motor belt fix screw and remove the keep plate.
d) Unfasten the two stepping motor assembly fix screws.
e) Lift the stepping motor assembly upward, then slide it to the left to remove from the metal belt.
f) Disconnect the stepping motor assembly cord from the hook.
4-6-2 Stepping Motor Assembly Mounting Adjustment
a) Keep the metal belt in the loop form, insert the stepping motor assembly, mount the metal belt
and keep plate with screws.
b) Align the oval hole of the stepping motor mounting plate with the guide pin and mount the
stepping motor assembly with two screws.
Temporary tightening of screws are required.
c) Pull the tip of the metal belt and mount the metal belt on the tip of the head assembly with ascrew.
d) Move the head assembly back and forth and check that the metal belt is not twisted. If twisted,
slightly loosen the metal belt fix screws on the stepping motor assembly and head assembly, and
move the head assembly back and forth several times.
Fasten the screws tightly.
e) Place the stepping motor assembly cord on the hook.
f) Mount the printed circuit board as described in 4-1-2.
g) Adjust the radial track after mounting. (Refer to 5-2).
Caution: Do not reuse the metal belt removed from the head assembly.
4-7 Head Assembly Exchange (See Figure 4-7)
4-7-1 Head Assembly Removal
a) Remove the printed circuit board as described in 4-1-1.
b) Remove the lever as described in 4-2-1
.
c) Remove the front plate as described in 4-3-1.
d) Remove the eject assembly as described in 4-4-1.
e) Remove the lever framne assembly as described in 4-5-1
.
f) Remove the stepping motor assembly as described in 4-6-1.
g) Unfasten the PCB post fix screws and remove the PCB post.
h) Unfasten the two screws fastening the guide shaft keepers Aand Band remove keepers Aand B.
i) Lift the guide shaft rear edge and remove the guide shafts in abackward direction, individually. Be
careful not to damage guide shafts or mix the right and left shafts.
j) Carefully remove the head assembly.
4-7-2 Head Assembly Mounting and Adjustment
a) Fit the two guide shafts in the head assembly without mixing the right and left, and mount in the
housing while holding the guide shaft.
b) Secure guide shaft keepers Aand Busing four screws.

c) Secure the PCB post using screws.
d) Mount the stepping motor assembly as described in 4-6-2.
e) Mount the lever frame assembly as described in 4-5-2.
f) Mount the eject assembly as described in 4-4-2.
g) Mount the front plate as described in 4-3-2.
h) Mount the lever as described in 4-2-2.
i) Place the printed circuit board as described in 4-1-2.
j)Adjustthe radial track(5-2) and index burst time (5-5), and checktheO track sensor(5-3),
azimuth (5-4), level (5-6), resolution (5-7) and symmetry (5-8) after mounting.
4-8 Spindle Motor Assembly Exchange (See Figure 4-8)
4-8-1 Spindle Motor Assembly Removal
a) Remove the printed circuit board as described in 4-1-1.
b) Remove the lever as described in 4-2-1.
c) Remove the front plate as described in 4-3-1.
d) Remove the eject assembly as described in 4-4-1.
e) Remove the lever frame assembly as described in 4-5-1
.
f) Unfasten the four spindle motor fixing screws (three screws on top and one screw on
the bottom).
g) Remove the spindle motor in adownward direction. Be careful not to damage the top surfaces of
the spindle.
4-8-2 Spindle Motor Assembly Mounting Adjustment
a) Secure the spindle motor with four screws. Align the W/P LED approximately the
centre of the housing hole.
b) Mount the lever frame assembly as described in 4-5-2. ^
c) Mount the eject assembly as described in 4-4-2.
d) Mount the front plate as described in 4-3-2.
e) Mount the lever as described in 4-2-2.
f) Place the printed circuit board as described in 4-1-2.
g) Adjust the spindle speed (5-1 ), radial track (5-2), track sensor (5-3) and index burst time (5-5)
and check the azimuth (5-4), level (5-6), resolution (5-7), symmetry (5-8) and write protect sensor (5-
9) after mounting.
4-9 Track Sensor Assembly Exchange (See Figure 4-9)
4-9-1 Track Sensor Assembly Removal
a) Remove the printed circuit board as described in 4-1-1.
b) Unfasten the track sensor assembly fix screw.
c) Remove the track sensor assembly.
4-9-2 Track Sensor Assembly Mounting and Adjustment.
a) Mount the track sensor assembly with screws.
Temporary tightening of screws is required.
b) Place the printed circuit board as described in 4-1-2.
c) Adjust the track sensor after mounting. (Refer to 5-3).
4-10 Metal Belt Exchange (See Figure 4-10) ^
4101 Metal Removal
a) Remove the printed circuit board as described in 4-1-1.
b) Remove the lever as described in 4-2-1.
c) Remove the front plate as described in 4-3-1.
d) Remove the eject assembly as described in 4-4-1.
e) Remove the lever frame assembly as described in 4-5-1.
f) Remove the stepping motor assembly as described in 4-6-1.
g) Remove the head assembly as described in 4-7-1.
h) Unfasten the metal belt fix screws and remove the metal belt from the head assembly.
4102 Metal Belt Mounting and Adjustment
a) Mount the metal belt on the head assembly using screws. (Be careful of the metal belt direction).
b) Mount the head assembly as described in 4-7-2.
c) Mount the stepping motor assembly as described in 4-6-2.
d) Mount the lever frame assembly as described in 4-5-2
e) Mount the eject assembly as described in 4-4-2.
f) Mount the front plate as described in 4-3-2.
g) Mount the lever as described in 4-2-2.
h) Mount the printed circuit board as described in 4-1-2.
i) Adjust the radial track (refer to 5-2), index burst time (5-5), and track sensor (5-3) after mounting.
10

5. Adjustments and Checks
5-1 Spindle Speed Adjustment
a) Insert and clamp ablank diskette by rotating the motor.
b) Stop on track.
c) Connect the frequency counter to TP6.
d) Rotate the speed adjusting variable resistor on the spindle-motor printed circuit board and
adjust so that the counter shows 200 +2 ms.
If the spindle-motor is not an adjusting variable resistor type, check the counter shows
200 ±2 ms only and adjusting is unnecessary.
fc^_
5-2 Radial Track Adjustment
a) Insert aCE diskette.
b) Move the head to Track 16and check the cat's-eye waveforms of the top and bottom heads.
c) Adjust as follows if one of the top or bottom heads is not more than 75% in an amplitude ratio of
two waveforms.
d) Slightly loosen the fix screws of the stepping motor assembly and move the stepping motor
assembly back and forth to adjust the amplitudes. The amplitudes of two waveforms should be
nearly the same. Then tighten the rear screw.
e) Check the cat's-eye waveforms of the top and bottom heads.
f) Repeat from d) if adjustment fails.
Measuring Conditions
Channel 1-TP1 (10mV/div) MODE-ADD
Channel 2-TP2 (10mV/div) Sweep-20ms/div
Head Reading Outouc Signal (TP1 -TP2)
—XI2; 75%
b
Fig. 5-
11

2Tracks at the minimum access time between
5-3 Track Sensor Adjustment
a) INsert aCE diskette.
b) Continuously seek between and
tracks of DFC222A specifications.
c) Adjust the track sensor assembly so that the step signal and track one are always on the
timing as shown in Figure 5-3.
Then secure with ascrew.
Measuring Conditions
Channel 1-TP4 (0.2V/div) MODE-DUAL
Channel 2-TP8 (0.2V/div) Sweep-10ms/div
A
Step Signal
TK Signal
2TK 1TK QTK 1TK 2TK
Direction J
5-4 Azimuth Check
a) Insert aCE diskette.
b) Move the head to Track 34 and check that the azimuth waveforms of the top and bottom heads
are as described in Figure 5-4.
c) Exchange the head assembly if the azimuth of one of the top and bottom heads is not as shown in
Figure 5-4.
Measuring Conditions
Channel 1-TP1 (10mV/div) MODE-ADD
Channel 2-TP2 (10mV/div) Sweep-1 ms/div
Trigger—TP6
<\
L) Wher. a>d (negative")
v.. =- V,
Shows tiinuta
2"> Vher. a<d (positive)
Ymsz be c2c.
abed
Shows misalignment by -IS'. Shows misalignment bv +13'
Head azimuth «0°-18'.
Fig. 5-4
12

5-5 Index Burst Time Adjustment
a) Insert aCE diskette.
b) Move the head to Track 34 and check the index burst times of top and bottom heads. Adjust as
follows if the timing of one of the top or bottom heads is not as shown in Figure 5-3.
c) Move the index sensor assembly back and forth by slightly loosening the index sensor assembly
fix screws to adjust the index burst time.
d) Check the index burst times of the top and bottom heads.
e) Repeat from c) if adjustment has been unsuccessful.
Measuring Conditions
Channel 1-TP1 (10mV/div) MODE-ADD
Channel 2-TP2 (10mV/div) Sweep-0.1 ms/div
Trigger- Edge Connector J2 8pin. Slope (••)
IND
HeadReading Output Si
(T P I-T?1)!00:£00jj s
270mV.
5-6 Level Check
a) Insert ablank diskette.
b) Move the head to Track 39 and write 2F by the top and bottom heads.
c) Check that the average output level of the top and bottom heads is more than
Perform the following if the output level is below the required standard.
d) Insert another blank diskette and reconfirm.
e) Check the spindle speed as described in 5-1.
f) Change the oscilloscope to the CHOP mode and check the TP1 and TP2 outputs. Exchange the
printed circuit board if one output is small or missing, even if the probes are normal.
g) Exchange the head assembly if no problems are encountered in d), e). and f) above.
Measuring Conditions
Channel 1-TP1 (10mV/div) MODE-ADD
Channel 2-TP2 (10mV/div) Sweep-20ms/div
Trigger—TP6
Head Reading Out Signal (TP1-TP2)
^%>wi&P* ^*=*hmji^
AA=270 mV I" in
13

5-7 Resolution Check
a) Insert ablank diskette.
b) Move the head to Track 39, write 1Fand 2F by the top and bottom heads, then measure the
average output level.
c) The resolution is higher than 55%, and calculations shall be as follows:
2F output (mV)/1 Foutput (mV) x100>55%
Measuring Conditions
Channel 1-TP1 (10mV/div) MODE-ADD
Channel 2-TP2 (10mV/div) Sweep-20ms/div
Trigger—TP6
2F average output level
Resolution =
1Faverage output level
95% or less with TKO
55% or more with TK39
5-8 Symmetry Check
a) Insert ablank diskette.
b) Move the head to track and write 1Fby the top and bottom heads.
Measuring Conditions
Channel 1-TP5 (0.1V/div) MODE--CH1
Trigger—INT.CH1 Sweep-0.5ms/div
Slope(+)
T=400 ns or less
(If you have individual spec, this item obey your spec.)
5-9 Write Protect Sensor Check
Load and unload adiskette and check that write protect sensing is definitely made using Brikon.
5-10 Head Cleaning
Check for excessive dust or oxidised magnetic iron powders on the load pad using such adentist's
mirror. Clean the heads using acloth that produces no flues or an applicator dipped in 91%
isopropyl alcohol. Clean the heads carefully and remove accumulated dust and oxidised magnetic
iron powders. Wipe the head using a cloth that produces no flues.
14

FD-3 EXPLODED VIEW
THIS DRAWING REFERS TO ALL THOSE DESCRIBED IN THE TEXT
J§ -5
15

16

17

ELECTRICAL PARTS LIST
Decription Circuit Reference Part No.
Metal Oxide Resistors
0.22ohm/y2WR544, 545 171584
0.22ohm/1W R547-550 171585
0.33ohm/2W R504 171072
1ohm/1W R415 171069
47ohm/1W R520 171586
56ohm/1W R541 171587
56ohm/2W R511 171588
100ohm/1W R407 171589
470ohm/1W R428 171590
1kohm/1W R506 170406
2.2kohm/1W R513 171591
4.7kohm/2W R802 171076
22kohm/3W R512 171592
82kohm/1W R509 171593
Fuse Resistors
1ohm/1/2W R427 171594
10ohm/1AW R516 809256
22ohm/1/2W R426 171595
39ohm/1/4W R406 171596
1kohm/1/4W R515 171597
Cement Resistors
5.6ohm/5W |R501 1422133
Ceramic Capacitors
680pF C540 1400213
2000pF/4kV C539 170430
0.001 5uF/500V C524 171598
0.0022uF/2kV C502-504 1400223
0.0056uF/500V C516, 520, 527 171599
0.01uF/1kV C508 171600
Electrolytic Capacitors
10UF/25V C427 171601
10uF/160V C429 171602
150uF/400V C505 171603
220uF/35V C435 20055
330uF/35V C517 171604
470uF/16V C522 1400248
1000UF/10V C425 171605
1000uF/16V C530 1400158
1000uF/25V C521 171606
3300uF/16V C529 171607
3300uF/35V C525 171608
Metal Polycarbonate Capacitors
0.1uF/250V |C428 171609
Metal Plastic Capacitors
0.1uF/250VAC |C501 171610
Variable Resistors
VR201 Volume Rotary Gang
500ohm-10kohm 171611
VR204 VRSF 500ohm 171612
VR401 VRSF 500ohm 171613
VR402 VR Rotary 30kohm 171614
VR403 VRSF 10kohm 171615
VR404 VRSF2kohm 171616
VR405 VRSF 100kohm 171617
VR501 VRSF 5KO 171618
VR502-505, 507 VRSF 1kohm 171619
Switch
SW501 lPower On/Off Switch 171511
Circuit Reference Description Part No.
Coils &Transform ers
L201 CoreTridal L201 171557
L401 Coil Linearity 171558
L402 Coil Inductor 171559
L501 Coil Line Filter AC 171502
L502 Coil 171560
L503 Coil 171504
L506 Coil Core Tridal 171620
L801 Filter Line 171561
T401 Trans Horizontal Drive 171562
T501 Transformer Switching 171563
FB401 Flyback Transformer 171564
P.C. Boards PCB001 MM0018A 171565
PCB002 MS0053A 171566
Jack
Socket CRT 171567
Miscellaneous
CD201 Cord DIN 171568
CD402 Cord Jumper 171569
CD403 Cord Jumper 17lA||i
CD404 Cord Jumper
CD502 Cord DIN 171571
CD801 Cord Connector 171572
DY401 DY 171573
TH401 Thermistor 171574
V801 Tube, Cathode Ray
340AXBWDN 171575
Fuse Fuse 3.1 5A(T) 171621
PC-CM
I.C.'s
IC101 I.C. OEC9001 1771477
IC102 I.C. TC74HC02P 171622
IC401 I.C. UPC1378H 170444
IC402 LA7820 1400368
IC501 STK7356
IC502 L78M12 190062
IC503 L78M05 190063
IC601 STK7358 171479
IC602 BA6993 171480
IC603 LA6324 170112
IC604 BA707 171481
ICP501.502 ICP-N75 171075
ICP503 PFR-315-F003 1714
171 &S ICP601 ICP-N50
Transistors
Q101-103, 105- 2SC1815 170447
113, 401, 601,
602, 610-612,
616, 618, 801-
803
Q401,402,603, 2SA1015 170453
606,607,613,617
Q403 2SD1426 171484
Q404 2SC2271 170449
Q604, 605 TLP580 171485
Q608, 609, 615 2SD1207-T 170451
Q614 2SB1134R 171486
Q804-806 2SC3789 171487
--.,.- --.
18

ELECTRICAL PARTS LIST
Reference Description Part No.
Resistors
5.6ohm Fuse
1kohm R181
R189-194 10061
Resistor Network
NR101
NR102
NR103
NR104
NR105
NR801
4.7kohm x7
1kohm x5
2.2kohm x6
2.2kohm x5
4.7kohm x8
Lkohm x10
Ceramic Capacitors
47pF NPO
0.1 uF
TC101
C805, 806
C504-506, 802, 803
Trimmer 200pF Ceramic
Electrolytic Capacitors
47uF/16V !C801
Crystals
X101
X102
X103
m
X801
Crystal HC49U.843M
Ceramic Oscillator
Crystal DSVT30032K
Crystal HC18RW24.0
Crystal HC18RW28.636
Ceramic Oscillator KBR-6.0M
Coils
Inductor Coil L101, 102
Jacks &Connectors
14 Pin DIL
8Pin DIL
20 Pin DIL
9Pin DSKT
Mate NLock
Mate NLock
Socket DSub
DIN Cord 6Way
J101, 102
J1 03-1 20
J121, 122
J801
CD101
CD104
CE101-103
CD801
Semiconductors
Description
Diodes
DS442X-BT
TLS134A LED
Reference No.
D101-104, 501, 502,801
D503
171666
171667
171668
171669
171670
171671
171672
171058
171371
20027
171372
171373
171374
171375
171376
171377
171404
170120
170119
170121
171408
171673
171674
171675
171420
Part No.
1422117
171403
IC's
MC1488P IC101 171378
1489AP
•«r7406P IC102, 103 171379
IC104 171380
DN74LS373 IC105, 122 170108
INS8250N IC106 171381
DN74LS240P IC107, 117 171382
DN74LS244 IC108, 115, 121, 124 171383
MBL8259A-2P IC109 171384
DN74LS125P IC110 171385
SED9420CAC IC111 171034
UPD765AC-2 IC112 40018
DN74LS174P IC113 171387
UPD8253C-5 IC114 171388
DN74LS14P IC116 171389
AMS40040 IC118 171391
MBL8086-2P IC120 171392
DN74LS245P IC123 171393
AMS40039 IC125 171577
AMS40041 IC126 171394
AMS40045 IC127 171395
TC74HCUD4P IC128 40008/A
AMS40043 IC129 171396
UPD8237AC-5 IC130 171397
UPD4126C-15 IC131, 133 171398
AMS40044 IC132 171578
MC146818P IC134 171399
MN41256-15 IC135-152 171400
LA4140 IC401 170111
AMS40042 IC801 171401
TC74HC14P IC802 171033
Description Circuit Reference Part No.
Transistors
2SC1815Y
2SA1015Y
KTC2120
Q101, 102, 105
Q103, 104, 106, 107
Q1 08-1 13
170447
170453
170113
Switches
SW801 Switch Key Board 171409
Variable Resistors
VR401 Volume Control CPU Unit 171579
PCB Assy's
PCB101
PCB102
PCB801
CPU PCB MC0032B
LED PCB MC0033B
Part of PCB101
Keyboard PCB MK002A
171410
171412
PC-MM
Intergrated Circuits
IC201
IC401
IC402
IC501
IC502
IC503
IC504
TC74HC04 40008/A
AN5753 151040
UPC1031H2 171546
STK7356 171478
BA6993 171480
LA6324 170112
BA707 171481
502 ICP-N50 171547
Transistors
Q201-203, 205,
401,506, 511, 512
Q204, 520
Q402
Q501, 502, 514,
518, 519
Q503, 507, 508,
517
Q504, 505
Q507
Q509, 510, 516
Q513, 515
Q801
2SC1815
2SA1015
2SD1159
2SC536
2SA608
TLP580
2SC2229
2SD1207
2SB1134R
2SC2229
Diodes
D207
D208, 401,402,
410,512, 513, 517
521, 524, 525
D403
D404, 405, 407
D406
D408
D409
D501-504
D505
D506
D507
D508-510
D511, 526, 527
D514
D515
D516
D517
D520, 801
D522
D523
D528-531
D.Z. MTZ5. 1BT-77
D. ISS231T-77
C. 11E2TA1 Diode Silicon
D.10ELS4 Diode Rectifier
D.11E1TA1 Diode Silicon
D.Z. GZA6.2Y Diode Zener
D.KDS1555 Diode Silicon
D.20E10FA13
D.Z. GZB18B
D.DFC15L-KC5
D.Z. GZB9.1B
D.DFH10G-KB4
D.Z. GZA18YBT
D.30DF2
DSF 10B
D.F5KQ60
D.F10PO4Q
D.DS442X-BT
D.Z. MTZ5.1BT
D.Z. MTZ5.6BT
D.KDS1555
Carbon Film Resistors
330ohm/1/4W R572
470ohm/1AW R571
10kohm/1/4W R573
75ohm/V2W R238-243
170114
170453
170623
150350
920113
171548
170624
170451
171486
170624
1422112
171582
171549
171550
171551
171552
800222
171048
171553
171491
171493
171492
171554
171555
171556
171496
171497
1422117
1422112
171499
810332
10044
10048
10085
151583
19

ELECTRICAL PARTS LIST
Circuit Reference Description Part No.
Diodes
D101-105
D106-115, 401-
405, 407-409,
505, 608, 609,
613, 616-620
D406, 412, 413,
610
D410
D411
D501-
D506,
D507,
606
D508,
D510
D511
D601
D607
D611
D612
D614
D615
504
603
509, 604-
602
MTZ6.8BT-77
ISS132T-77
DFD05G
D.Z.MTZ11BT
C.BB4-FC
20E10FFA13
DFC15L-KC5
DFH10G-KB4
GZB9.1B
30DF6-FC
SR-2M
GZB18B
GZA18Y
F5KQ60
F10PO4Q
MTZ5.1BT-77
MTZ5.6BT-77
Carbon Film Resistors
75ohm |R1 54-1 58
Metal Oxide Resistors
0.22ohm/y2W
0.33ohm/2W
1ohm/3W
4.7ohm/3W
15ohm/2W
47ohm/1W
56ohm/1W
68ohm/2W
100ohm/2W
1kohm/1W
2.2kohm/1W
3.3kohm/1W
3.9kohm/1W
4.7kohm/2W
5.6kohm/2W
22kohm/3W
33kohm/2W
82kohm/1W
R641-646
R604
R502
R438
R511
R624
R737
R512
R507, 612
R610
R613
R504
R503
R434
R805-807
R609
R508
R607
Fuse Resistors
0.82ohm/1W R442
1ohm/y2WR443
8.2ohm/1/4W R437
lOohm/'AW R510
100ohm/1/4W R412
100ohm/1/2WR444
470ohm/1/2WR509
1kohm/ViW R614
616
Cement Resistors
5.6ohm/5W R501, 601
Ceramic Capacitors
100pF C442
470pF/2kV C429
820pF/2kV C523
0.001 uF/2kV C801
0.001 5uF/500V C620
0.001 5uF/2kV C511, 514,807
0.0022uF/2kV C502, 604
0.0056uF/500V C612, 617
171488
171489
171490
171623
1422116
170848
171491
171492
171493
171494
1400122
171495
171624
171496
171497
171498
171499
10029
171625
171072
171077
171626
171627
171628
171629
171630
171631
170406
171632
171633
170407
171634
171635
171636
171637
171638
1422141
171639
170404
809256
171640
1400183
171641
171642
1422138
1422144
1400224
171643
1422147
171644
171645
1400223
171646
Description Circuit Reference Part No.
Polyester Capacitors
0.1ur/100V |C404 |1400237
Electrolytic Capacitors
1UF/250V C440 171647
10uF/100V C509 171648
22uF/250V C436 171649
150uF/400V C506, 601 171650
220uF/160V C515 171651
330uF/25V C613 171652
470uF/35V C516 171653
1000uF/16V C623 1422158
1000uF/35V C437 1522159
2200uF/35V C408 1422160
3300UF/16V C621.622 171654
3300uF/35V C618 171655
Metal Polypropylene Capacitors
0.0082 uF/1.6kV C430 171656
0.32MF/200V C433 171657
Metal Plastic Capacitors ^
0.1uF/250VAC |C501 |17l||p
Coils &Transformers
L401 Coil Line^.ty 171500
L402 Coil RX-9P-472K 171501
L501 Coil Line Filter AC PLA1022C 171502
L502 Coil Degauss 171503
L601 Coil 171504
L80 1-804 Coil ELO606RA-101K 171505
T401 Trans, Horizontal Drive 171506
T501 Tranformer, Switching 171507
T601 Transformer, Switching 171508
FB401 Transformer Flyback 171509
Switches
SW401 ISwitch Slide 171510
SW501 |Switch Push 171511
P.C. Boards
PCBO0
1
PCB MM0019A Monitor Main 171512
PCB002 PCB MS0054A CRT Socket/ 171513
Colour Drive
Jacks
J801 Socket, CRT 171514
JC801 Socket Cover CRT 171 l<W
Miscellaneous
CD101 Cord DIN 14 Pin 171519
CD601 Cord DIN 8Pin 171522
F501 FuseS506 3.15A(T) 171531
TH501 Degauss Element 171533
V801 Tube, Cathode Ray
M34EAQ1 0X-AT1 460/90 171534
ICP501, 502 ICP-N75 171057
ICP503 PRF-315-F003 171483
ICP601 ICP-N50 171547
Variable Resistors
VR101, 103 VRSF 1KOhm 171691
VR102 VR Rotary 500ohm-500ohm 171692
VR104 VRSF2KOhm 171616
VR401 VR Rotary 200Kohm 171693
VR402 VRSF5Kohm 171694
VR403 VRSF5Kohm 171695
VR404 VRSF500ohm 171612
VR601 VRSF5Kohm 171618
VR602-604, 606 VRSF 1Kohm 171619
VR801 VRSF 5Kohm Red 171696
VR802 VRSF 5Kohm Green 171697
VR803 VRSF5Kohm Blue 171698
VR804 VRSF 500ohm Red 171699
VR805 VRSF 500ohm Blue 171700
20