CONTENTS Page
Technical Specification 2 Safety Tests 2 Self-Test Activitation 3 Cabinet Drawing & Parts List 4&5 Flow Charts 6-9 PCB 10 & 11 Disk Drive Diagrams 12,13,14 Software Errors 15 Diagnostic Flow Chart 16 Self Diagnostic Tests 17 Circuit Diagram 18 & 19 Electrical Parts List 20
| Ref | Description | Part number |
| 1 | Cabinet top | 173017 |
| 2 | Switch Keyboard Assembly | 173019 |
| 3 | Disc drive EME-156 | 190005 |
| 4 | LED PCB Assembly | 172004 |
| 5 | Bracket Disc Drive | 173021 |
| 6 | Socket I/O | 170022 |
| 7 | PAL modulator Block | 172020 |
| 8 | 8-pin DIN socket | 172021 |
| 9 | BT/Interface socket | 172022 |
| 10 | 6-way Power DIN socket | 173026 |
| 11 | 9-way Joystick port | 170023 |
| 12 | Reset Switch | 172017 |
| 13 | Cabinet bottom | 173018 |
| 14 | Main PCB Assembly | 173023 |
| . | Gun Foot | 173021 |
Diagnostic Flow Chart
This chart must be used in conjunction with the alignment procedures
This chart is for information only and does not guarantee an exact diagnosis. For warranty purposes and faulty drive mechanism must be returned to Amstrad for replacement. Service agents should not attempt any repairs on the mechanism or to it's PCB part number 270312
Index period------------N---------------Motor rotation 200+/- 5 msec? | Y | Self-read error?--------N---------------Read Error | Y | Write error?------------N---------------Write Error | Y | Interchangeable---------N---------------Interchangeability Error lead? | Y | Disk Drive OK
Motor Rotation | | Does motor--------------N---------------Power Supplied? Rotate? | | | | | | Y N Y<--------------------------------<-| | | | | Check Wiring | | | Adjustable with---------N---------------Does it rotate VR201? normally by using------ | normal motor? | Y | N | Y | Adjust Time to 200 | Replace drive +/- 1 ms Replace motor
Read Error | | Test with disk EME - CF2 | | TR39 2F output-----------N-----Head touch OK?-----N-----Replace drive >= 140 mV | | | | Y Y | | | | Is head output---N------Replace head assembly Is TROO output------N 1 mV or more? =< 220 mV | | | | | Y | Y | | | Read/write error | | in all tracks?->----+--Y---------->-Replace Drive | N | Read error only-----------N-----------Seek Error----------N-------Replace drive in Specific track? | | | Y Y | | Replace disk | (inspect by drive) TROO output normal-----N-----Replace TROO | sensor | Y | | Replace drive
Write Error | | Error Continous?-----------N-----Check action in----------OK-------Check action in | seek failure flow | read failure flow------+ | | | | Y | Amplifier System | | | | Head system | | | | Write waveform-------------OK----------------------------->-+ | | in TP1.2 | Replace drive | | | | NG | | | | | Head Connector-------open---------Repair head connector | open or short? | | | |short | +--------------------------------------------------------------------+ | | Replace control PCB
Interchangable lead error | | + Off-track media----------N------------+ lead test | | | | | Y | | | | | - Off-track media----------N------------+-----------------Adjust positioning lead test | | Y | | Index timing---------------N------------Adjust index timing 0-1000 usec | | Y | | Media failure
PCB
Disk Drive Diagrams
Software Errors
If a drive fault is reported the fault may be a software problem. Before investigating the drive please carry out the following checks to ensure it is not a software problem.
Detection and Correction of "Soft Errors"
Soft errors are usually caused by the following reasons.
- Random external noise of several microseconds or less.
- Minute off-tracking and shifting of write timing that are
not detected during the write operation which can cause
the soft error during the read.
To remedy such soft errors, take the following procedures at the controller side.- Repetitive reading on the track by 10 times or more until the data is restored.
- When the data is not restored by step 1, access the head to the adjacent track in the same direction as move previously, and thereafter return the head to the original track.
- Repeat the step 1.
- If the data is not restored by the above steps. the error cannot be remedied
Write Error
When an error is caused during the write operation, the error is usually detected during the next rotation through the read operation called "Write check".
To correct the error, repeat the write operation again and carry out the Write check.
If the result is still incorrect even after the write operation is repeated more than 10 times, either the disc or the drive are working incorrectly. To find out the trouble source, carry out the read operations with another track. Should the error still be found. change the disk and repeat the above procedures. Should error still be found, the drive should be considered defective. If the error is removed, the original disk must be defective. Discard it.
Seek Error
- Step motor or step motor drive circuit is defective.
- The torque of the carriage is not correct.
Restoration procedures from the seek error.
make the re-calibration to the track 00. Then, carry out the re-seek to the original track
Notes:
- Always ensure the head is clean.
- Index/Sector Factor (Ready Defect)
As the unit has Optional Read Output
It is normally not ready until 2 revolutions are made after the
disk insertion.
Diagnostic Flow Chart
START--<--------------------------------------------------------------------------+
| |
| |
CHECK TV TUNED OK. TRY |
CHANNEL 36. VOLUME UP |
| |
| |
CONNECT PSU TO 240V |
AC MAINS. CONNECT TO |
TV SOCKET |
| |
| |
HOLD DOWN BREAK KEY |
AND PLUS IN 9V LEAD |
INTO COMPUTER |
| |
| NO NO |
RED LED LIGHTS UP?------------>-MAINS FUSE OK?-------->-REPLACE FUSE----------->--|
| | |
YES | | |
| NO | YES |
PICTURE/SOUND ON TV?----------->-+ +-----------------CHECK LED, PCB---->--+ |
| | CONNECTOR | |
YES | | | |
| | NO | |
PRESS AND RELASE ANY PICTURE---------->--CHECK MODULATOR,--->-| |
RESET BUTTON AT ALL? DC-DC CONVERTOR | |
| | | |
| NO |YES | |
MENU APPREARS?---------+ | | |
| | | | |
YES | | | | |
| | | YES | |
PRESS DOWN ARROW | ANY SOUND?--------------CHECK ULA, CPU---->--| |
| | |NO RAM, TEA 2000 | |
| NO | | | |
BLUE BAR ON MENU---+ | CHECK MODULATOR---------------------------->-| |
MOVES? | | SOUND COIL TUNING | |
| | | | |
YES | | +------>-CHECK ROM------------------------------->----| |
| | | |
SELECT 128K BASIC | | |
PRESS ENTER +---------->-CHECK KEYBOARD----------------------------->-| |
| | CONNECTORS, ULA | |
| | | |
TEST ALL KEYS | | |
| | | |
| NO | RECTIFY AND RETEST----<----------------------| |
ALL OK?------------+ | |
| | |
YES | | |
| +-------------------------------------------->--+
DO TAPE TESTS
SPECTRUM +3 SELF DIAGNOSTIC TESTS
The Spectrum +3 test software comes on a rom board. This should be plugged into the Expansion I/O slot of the +3. The +3 should also have a loopback cable plugged into the KEYPAD and RS232 sockets, two joysticks plugged in, and monitor, TV and audio amp connected.
Turn the machine on. One of two things will happen.
- A test card with some text will appear. Follow the instructions on the screen.
- No text or testcard. In this case, note the color of the edge of the screen. It will either be a steady color or flashing regularly with a predominant color. Consult the table below to find out which RAM chip has (probably) failed.
Color STEADY FLASHING
BLACK IC 17 IC 32
BLUE IC 18 IC 31
RED IC 19 IC 30
MAGENTA IC 20 IC 29
GREEN IC 21 IC 28
CYAN IC 22 IC 27
YELLOW IC 23 IC 26
WHITE IC 24 IC 25
If you follow the instructions on screen from the first occurrence, then everything should be self-explanatory, The RAM test, if it finds a fault, will give two numbers. The first is the address at which the fault was found, and the second is the bank of memory which contained the address. If the address is zero, then it is probably not a RAM fault, but a paging hardware problem. Note that there is no way to fail the keyboard test - if a key won't respond then you can progress no further.
The cassette test comes in two parts. The first cassette test is similar to the ULA sound test, and is the last test in the ROM program. The tone it asks you to hear is much quieter than the other noises. The second cassette test comes on a tape and is used when the BASIC is running. Turn on the Spectrum, wait for the menu to appear and then press ENTER. Then start the test cassette. After a short while, the words PROGRAM: Loading... should appear, and shortly afterwards some instructions will appear on the screen. Follow these to test the cassette unit.
Circuit Diagram
Electrical Parts List
Integrated Circuits
Reference no. Description Part #
IC1 Gate Array 40077 40077 IC2 Z80A CPU 40080 IC3-6 64K x 4 D.RAM 173001 IC7 256K ROM VERSION 173002 IC8 256K ROM VERSION 2 173003 IC9 TEA2000 172048 IC10 MC1376 172049 IC11 AY-3-8912A 40001 IC12 MC 1488 QUAD RS232 DRIVER 172039 IC13 MC 1489 QUAD RS232 REC 172038 IC14 74HCT273 173004 IC15 74HCU04 40005/A IC16 765 Floppy Disk Controller 40018 IC17 SED 9420 171034 IC18 74HC704 173008 IC19 74HC14 171033 IC20 74HCT00 40008 IC40 Pin Socket 170121 IC28 Pin Socket 170120
Transistors
TR1 TRBC3083/BC558B 172032 TR2-5 TRBC239B/BC549B 50008
Diodes
D1-4,6-31,33-35 D1N4148 190715
LED Red LTL 321lA 172004
Miscellaneous
Xl CrystaL 35.4690MHz 172067 X3 6MHz Ceramic Resonator 173011 X2 16.000MHz Ceramic Resonator 173013 Modulator UHF 172020 Aerial Lead 172065 9 Way D Plug 173015 Power Supply Unit 173034
Coils
L1 Inductance 2.2uH 172058 L3,4 Inductance l00uH 172060 L2 RF Choke 4.43MHz 4097 173016
Carbon Film Resistors
R45 47ohm 10020 R4,50,51,73 l00ohm 10032 R31-33.35-37,41 l50ohm 10036 R34 470ohm 10048 R77-81 680ohm 10052 R9-13,47 820ohm 10054 R6-8,44,46 lkohm 10061 R54,68-71,74 1kohm 10061 R14-19,56,60,85 lk5ohm 10065 R42,62,65,72 2k2ohm 10069 R52 3k3ohm 10073 R49 3k9ohm 10075 R53,63,64 4k7ohm 10077 R55,86 6k8ohm 10081 R1-3,5,20-30 10kohm 10085 R43,57,66,75,76 10kohm 10085 R59 l5kohm 10089 R83 33kohm 10097 R48 36kohm 172077 R58 39kohm 10099 R67 47kohm 10101 R84 68kohm 10105 R61,82 lMohm 10147
Ceramic Capacitors
C42,43 7 pF NPO 173027 C32 10 pF NPO 173028 C34 22 pF NPO 173029 C36 22 pF 150511 C22 33 pF NPO 173030 C33 47 pF NPO 173031 C25,26,49,50 l00 pF 1422144 C14-17 220 pF 400107 C24 330 pF NPO 173032 C18-21,44 0.00l uF 24027 C23,35,47 0.01 uF 24011 C45 0.047pF 24015 C1-7,9-12,28 0.luF 171058 C31,37,39,40,46 0.luF 171058
Electrolytic Capacitors
C13,27,38,41 luF/50V 20062 C8,29,30 l00uF/16V 20028