Amstrad PCW 10 Troubleshooting Guide
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The user manual Amstrad supplied with the Amstrad PCW 10, which dealers were still selling new in the mid-1990s, has not been put online, and no service manual for the machine is available.[1] The checks below use what is known of the PCW 10 itself: John Elliott's description of its printer and floppy controllers, the Joyce Computer Club's notes on the machine, and owners' advice for the PCW range. For supply and picture faults they point to the guide for whichever related board your machine turns out to have; see identifying the boards.[2][3]
Warning: the main unit contains the mains power supply and a CRT. Read CRT Discharge Procedure before opening it.
Start-up
[edit | edit source]Like the other PCWs, the PCW 10 has no boot ROM. At reset the hardware feeds the Z80 a short boot program, which loads the first sector of the disc in the drive; dot matrix and daisywheel PCWs use slightly different boot programs.[2] A blank screen with no disc in the drive is therefore normal.[4]
| Symptom | Probable cause | Action |
|---|---|---|
| Nothing at all: no screen, no drive activity | No mains, a blown mains fuse, or a supply fault | Check the lead and plug, then the mains fuse on the monitor board (F501, 3.15 A time-lag, on the 9256's board).[5] Find the cause of a blown fuse before replacing it. See power supply and picture. |
| Blank screen, no disc inserted | Normal | Insert a start-of-day disc.[4] |
| Blank screen with a disc inserted | A start-of-day disc for another PCW model, a damaged disc, or a drive fault | Use a start-of-day disc made for the PcW10; boot files cannot be exchanged between PCW models.[3] Then try a second known-good disc before suspecting the drive. |
LocoScript and CP/M versions written after the 9256 was released contain code that detects the 9256, 9512+ and PCW 10 floppy controller and whether the drives are 3.5-inch; earlier versions do not.[2]
Let a machine that has been in a cold loft or garage stand in a warm room for a couple of days before switching it on.[4]
Disc drive
[edit | edit source]The PCW 10's floppy controller is of the type used in the 9256 and 9512+. On these machines, commands for drive 2 appear to go to drive 1 but always report "ready", and selecting drive 3 selects both drives at once.[2]
- A drive that will not read any disc: clean the heads and check the drive as described in Floppy Drive Repair.
- A Gotek emulator that died on first power-up: Amstrad's drive power cable is not wired to the PC standard, and an unmodified Gotek is destroyed by it.[4] Check the cable before fitting a second one.
Printer
[edit | edit source]The PCW 10 uses the same printer controller design as the 8256, 8512 and 9256. The software talks to it through I/O ports FCh and FDh, and the controller reports its own faults by number.[2]
| Value | Meaning |
|---|---|
| 0 | Underrun |
| 1 | Printer RAM fault |
| 3 | Bad command |
| 5 | Print error |
| F8h | Normal operation, no error |
| Anything else | The software shows "No printer" |
Elliott's status bits for port FDh include the bail bar (in or out), the paper sensor, whether the head is at the left margin, and a controller fault flag.[2]
| Symptom | Probable cause | Action |
|---|---|---|
| "No printer" with a printer taken from another PCW | The printers are not interchangeable between the PcW10, the 9256 and the 8000 series | Use a printer from a PcW10.[3] |
| "No printer" with the PcW10's own printer | Cable not seated, or a fault in the printer or its controller | Switch off, reseat the single printer cable, which also carries the printer's power, and try again.[3] Much of a PCW printer's circuitry is inside the computer itself, so try a second PcW10 printer before condemning the first.[4] |
| Printer waits for paper or will not print | Bail bar out, no paper, ribbon or head lever | Work through the user checks in the 8256 guide; the 8256 and 9256 use the same printer mechanism, Amstrad part 171127.[5] |
Power supply and picture
[edit | edit source]No supply or monitor figures for the PCW 10 have been published. Read the board numbers first (see the maintenance guide).
- If the monitor board is the 9256's MM0059, Amstrad's 9256 chart applies: outputs measured at connector A under load, 12 V set with VR502 and 5 V with VR501, and 24 V checked with no adjuster. The fault tables are in the Amstrad PCW 9256 Troubleshooting Guide.[5]
- If it is the 9512+'s MM0041A, use the Amstrad PCW 9512+ Troubleshooting Guide.
- If it matches neither, record the board number and the output voltages you measure, and treat any figure from the other manuals as unconfirmed.
A low or noisy output that will not adjust points to the supply's electrolytic capacitors; see the Amstrad PCW 10 Capacitor Replacement Guide and Capacitor Failure Symptoms.
Keyboard
[edit | edit source]The keyboard plugs in at the front of the main unit, beside the drive.[3] The PCW keyboard sends its data serially; the data and clock lines both rest high, and the keyboard pulls the clock low for each bit.[2] Elliott lists three option links inside PCW keyboards. With LK1 connected the keyboard goes into a test mode, repeatedly sending test patterns with the Shift Lock LED lit all the time, so if a keyboard types rubbish with Shift Lock permanently lit, check whether LK1 has been bridged.[2] Keyboards are interchangeable across the range according to the Joyce Computer Club, so a keyboard from a PcW9256 or another PcW10 is a quick test.[3][6]
Expansion port
[edit | edit source]The expansion edge connector is low and horizontal, and add-ons built for the 8256 and 8512 need an extension cable to fit.[3] Remove every add-on before diagnosing a machine that will not start.
Related pages
[edit | edit source]- Amstrad PCW 10 · Amstrad PCW 10 Maintenance Guide · Amstrad PCW 10 Capacitor Replacement Guide
- Amstrad PCW 9256 Troubleshooting Guide · Amstrad PCW 9512+ Troubleshooting Guide · Amstrad PCW 8256 Troubleshooting Guide
- Floppy Drive Repair · CRT Discharge Procedure · Capacitor Failure Symptoms
References
[edit | edit source]- ↑ 8BIT issues 12 and 13, small advertisements: "PcW10 printers not working", "PcW10 keyboards not working", "PcW10 manual new" (issue 12); "PCW10 user manual, new" (issue 13). Scans at archive.org/details/8Bit-fanzine-12 and archive.org/details/8Bit-fanzine-13. Retrieved 2026-10-19.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 John Elliott, PCW Hardware. Hosted as File:PCW Hardware Reference (John Elliott).pdf, described at Amstrad PCW Hardware Reference (John Elliott). Section 2 (boot process; separate boot programs for dot matrix and daisywheel PCWs), section 6.1 ("PCW8256/8512/9256/10 printer controller": ports FCh and FDh, controller error numbers, status bits), section 8.2 (drive decoding on the 9256, 9512+ and 10), section 8.3 (the controller probe), section 10.2 (keyboard option links; LK1 test mode), section 10.4.1 (keyboard wire protocol).
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Joyce Computer Club (Amsterdam), "PcW 10 Gallery", fvempel.nl, last updated 29 July 2007. Retrieved 2026-10-19. A look-alike of the PcW 9256 with the same keyboard and 9-pin printer; 512 KB and a 3.5-inch drive; boot files not interchangeable between models; the printer not interchangeable with the 9256 or 8000-series printers; keyboards interchangeable; rear ports; the low expansion connector.
- ↑ 4.0 4.1 4.2 4.3 4.4 Richard Lloyd, PCW article, Amstrad CPC User Club Magazine (ACUC) issue 1, June 2022. Scan at archive.org. Retrieved 2026-10-19. A PCW started without a suitable disc shows a blank screen; much of the circuitry of a PCW printer is inside the PCW itself; a machine stored in a loft or garage should acclimatise for a couple of days; the non-standard drive power cable and the Gotek; the PCW 10 as an updated 9512 sharing many features with the 9000 series.
- ↑ 5.0 5.1 5.2 Amstrad plc, PCW9256 Personal Computer Word Processor Service Manual. Hosted as File:Amstrad PCW 9256 Service Manual.pdf, described at Amstrad PCW 9256 Service Manual. Alignment chart p. 3 (supply outputs at connector A; strobe timing with VR701 and the RP3); electrical parts list pp. 16–17 (printer mechanism 171127).
- ↑ 8BIT issue 16, small advertisements: "keyboard to fit PcW10/PcW9256", "Dot matrix printer to fit PcW10". Scan at archive.org/details/8Bit-fanzine-16. Retrieved 2026-10-19.