Psion Series 5 Troubleshooting Guide
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Psion's service manual for the Psion Series 5 (1997) includes a final test procedure that lists the fault codes Psion's test rig printed and the assembly to change for each, which makes it the best starting point for diagnosis.[1] The Psion Series 5mx looks almost the same but its main board, screen and screen cable are different parts.[2][3] A Series 5 has a CL-PS7110 processor at 18.432 MHz and 4 MB or 8 MB of RAM; a 5mx has Psion's Windermere chip at 36 MHz and 8 MB or 16 MB.[1][4]
Preliminary and power-up checks
[edit | edit source]- Back up first. Removing both the main cells and the lithium cell without external power erases the internal memory. Release the lithium cell with the stylus, not a metal tool.[1]
- Some battery brands are shorter than the European average and make poor contact, which gives false low-battery warnings. Rechargeable cells run for a short time and can look like a fault.[1]
- Test peripherals, links and power supplies with a Series 5 that is known to work, because they cause faults of their own.[1]
- A crash can usually be cleared with a soft reset, but Psion advises fully testing a machine that has crashed, because an intermittent hardware fault can cause one.[1]
- Check the battery current in the System screen's Battery Information (Shift-Ctrl-P). With no external power and the backlight off it should be below 50 mA.[5]
Resets
[edit | edit source]| Reset | Mechanism | Effect |
|---|---|---|
| User (warm) reset | A switch built into the lithium cell's negative contact, pressed with a pointed instrument through the backup cell cover | Warm restart; user data should be kept |
| Power-on (cold) reset | Ricoh RN5VLR20AA voltage detector (IC4), tripping when VDD crosses 2.0 V ±2.5 % | Erases everything in volatile memory; means all power was lost and restored |
Psion's fault codes list a lithium reset contact that is permanently pressed down as a cause of a failed test, with the fix of bending the contact away from the board.[1]
Fault codes from Psion's final test
[edit | edit source]Psion's final test rig printed a numbered Fail Ticket for each failure, giving what to check and which assembly to change.[1]
| Code | Diagnostic | Check | Change |
|---|---|---|---|
| 01 | Too much current | PCB | |
| 03 | No response | Battery module contacting the positive contact | Re-test, ensuring contact |
| 03 | No response | Unit's battery spring clip present | PCB battery spring |
| 03 | Did not respond to wake-up signal (DSR) | Expansion connector DSR | PCB expansion connector |
| 03 | Did not boot into test program (no DTR) | Expansion connector DTR | PCB expansion connector |
| 04 | Failed Tx/Rx communication | CompactFlash fully inserted | Re-test, ensuring it is fully home |
| 04 | Failed Tx/Rx communication | CompactFlash door fully shut and card detected | Plastic cam operator; PCB door switch |
| 04 | Failed Tx/Rx communication | ROM board connections | PCB ROM board connector |
| 04 | Failed Tx/Rx communication | Lithium reset contact permanently down | Bend the contact away from the PCB |
| 06 | Language, RAM size | Test program setup | Wrong unit build |
| 07 | Standby current out of limits | DRAM; dry joints, floating inputs; shorts from metallisation of plastics onto the PCB | PCB; dictaphone plastics |
| 08, 10 | LCD connector | LCD | |
| 09 | Backlight connector | Backlight | |
| 11 | Keyboard connector; keys | Keyboard; keys | |
| 12 | Expansion connector Tx, Rx | PCB expansion connector | |
| 13 | Expansion connector RTS, DTR, CTS, DSR, DCD | PCB expansion connector | |
| 14 | IrDA not blocked | PCB IrDA devices | |
| 15 | Lithium cell in socket; dry joints on lithium contacts | PCB; lithium contacts | |
| 16 | DC jack lead properly inserted | PCB DC jack socket | |
| 17 | Expansion connector Vin2+ and ground | PCB expansion connector | |
| 18 | Expansion connector shield | PCB expansion connector | |
| 19 | Expansion connector Vpc | PCB expansion connector | |
| 22 | Unit properly seated; speaker fitted correctly | Speaker | |
| 23 | Unit properly seated; microphone fitted | PCB microphone | |
| 24 | Case switch not broken, stuck open | PCB case switch | |
| 25 | Digitiser connections | Digitiser | |
| 26 | Action of dictaphone buttons | Plastics; PCB dictaphone switches | |
| 27 | Case switch not broken, stuck closed | PCB case switch | |
| 28 | Dictaphone status LED | PCB status LED | |
| 29 | Plastic cam operator of CompactFlash door | Plastics; PCB CompactFlash door switch | |
| 31 | Removed lithium and CompactFlash | PCB | |
| 33 | ROM board devices | Test program setup | Wrong unit build |
Power and current
[edit | edit source]Psion's standby current limits, measured at 2.75 V with the processor asleep, are 1.50 mA for the 4 MB model and 2.10 mA for the 8 MB model.[1] Above those, Fail Ticket 07 points at the DRAM, dry joints or floating inputs, or shorts from metallised plastic onto the board.[1] The final test starts the machine at 2.50 V with the supply limited to 65 mA, and requires the current to be below 10 mA before continuing; the DC jack is tested at 6 V, limited to 500 mA.[1]
The DC input socket is 6 V, centre positive.[6] Psion's DC jack test also checks the ground return separately, to catch a break in the toroidal input filter.[1]
Display and digitiser faults
[edit | edit source]| Symptom | Probable cause | Action |
|---|---|---|
| Horizontal lines across the display, often after opening the lid | Cracked screen ribbon cable[3] | Back up, then replace the cable; the Series 5 cable differs from the 5mx's. See Psion Series 5 Hinge Cable Repair |
| Display works only with the lid part open | Cracked ribbon cable[3] | Back up at once with the lid about a centimetre open[3] |
| No display at all | Ribbon cable, LCD connector or LCD (Fail Tickets 08 and 10)[1] | Back up blind: serial cable to PsiWin, Ctrl-L, Cable, down arrow, 5 (57,600 baud), Enter[5] |
| A grey vertical band | A failed screen controller component[5] | Replace the LCD assembly |
| Backlight dead | Backlight connector or backlight (Fail Ticket 09)[1] | Psion warns that the backlight is delicate and easily damaged during servicing[1] |
| Pen taps land in the wrong place | Calibration lost; the factory calibration is kept, but any user calibration is lost when the machine loses all power[1] | Recalibrate |
| Touchscreen does not respond | Digitiser connections (Fail Ticket 25)[1] | Check the digitiser flex and its clip |
Memory and CompactFlash faults
[edit | edit source]- Psion notes that certain intermittent faults come from dry or faulty joints on the ROM daughter board, and suggests swapping it early to check. Do not bend it; it cracks. A replacement must have the same OS build and language, shown in the System screen with Ctrl+H.[1]
- Peter Vis traced a Series 5 that intermittently failed to see all its memory to green oxide on the daughter board's pins, and cured it by cleaning the socket and pins with contact cleaner.[7]
- The machine only boots from a CompactFlash card when the CompactFlash door switch is closed. Psion's check is to select drive D in the System screen and open and close the door to see whether the card is detected.[1]
Keyboard, sound and switches
[edit | edit source]| Symptom | Probable cause | Action |
|---|---|---|
| Keys dead | Keyboard flex or keys (Fail Ticket 11)[1] | Reseat the blue keyboard flex squarely in its socket[1] |
| Dictaphone button sticks | Button plastics or the switches on the board (Fail Ticket 26)[1] | Psion treated any button that did not release on its own as a fault[1] |
| No sound | Speaker seating or speaker (Fail Ticket 22)[1] | Check the speaker flex |
| Machine does not react to the case opening or closing | Case switch stuck open or closed (Fail Tickets 24 and 27)[1] | Check the switch on the main board; when refitting the base, have the case open so the switch is not fouled[1] |
Related pages
[edit | edit source]- Psion Series 5
- Psion Series 5 General Maintenance
- Psion Series 5 Hinge Cable Repair
- Psion Series 5 Service Manual
- Psion Series 5mx Troubleshooting Guide
- Battery Explosion, Capacitor or Corrosion Damage
- Recommended Tools
References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 Psion Computers PLC, Series 5 Service Manual, November 1997. Hosted on this wiki as File:Psion Series 5 Service Manual (November 1997).pdf. Introduction (PDF p. 4), circuit description (pp. 6–7), disassembly precautions and daughter board (pp. 17–18), reassembly and fault notes (pp. 26–27), explanation of tests and standby current (pp. 43–44), Fail Ticket codes (p. 45).
- ↑ "Psion Series 5", Wikipedia. Non-interchangeability of Series 5 and 5mx internals.
- ↑ 3.0 3.1 3.2 3.3 David Savery, "Psion Series 5MX disassembly and screen cable repair", R3UK, 6 July 2004. Screen ribbon failure, the part-open workaround and the different Series 5 ribbon.
- ↑ Ash Wolf, "'16 Shades of Grey' – Building a Psion/EPOC32 Emulator", 27 December 2019. Processor identification for the Series 5 and 5mx.
- ↑ 5.0 5.1 5.2 "Series 5mx/5/MC218 specific", The EPOC FAQ(ish). Battery Information check, backing up with a dead screen, the grey vertical band and Psion's screen-replacement practice.
- ↑ Peter Vis, "Psion Series 5 Power Supply", petervis.com.
- ↑ Peter Vis, "Psion Series 5 Memory Board – Repair", petervis.com.