Psion Series 7 Troubleshooting Guide

Psion's own layout diagram. The badge on the keyboard bezel — not labelled here, but sitting between the 6 and 7 keys — is what Psion's support advice tells you to press firmly to reseat the screen cable. Note also the microphone, the small hole to the right and front of the keyboard that is routinely mistaken for a reset hole.

The reset button is here: inside the lithium backup battery compartment on the underside, beside the coin cell.

Fault-finding for the Psion Series 7 and, for everything mechanical and electrical, the Psion netBook — the two share the same motherboard and the same case. Faults specific to the netBook's OS-from-CompactFlash arrangement are in the Psion netBook Troubleshooting Guide; the Windows CE machine has its own page at Psion netBook Pro Troubleshooting Guide.

No Psion service manual for the Series 7 or netBook is known to survive. Unlike the Series 5, there is no published exploded view, parts list or factory fault-code table for these machines. Everything below comes from Psion's own support answers, the contemporary community FAQ, or documented owner experience, and is cited accordingly.

⚠️ Before you start

• Back up first. The internal disk is RAM. Diagnosis on these machines involves removing batteries, and there are documented ways to lose the lot — see below.
• Remove all batteries, main and backup, before opening anything or changing the ROM/memory module.
• There are no mains voltages inside the machine. The external supply is 15 V at 1.5 A per Psion's own datasheet; the community FAQ says 15.5 V. The Li-ion pack deserves respect in its own right — see Psion Series 7 Battery Service.
• Anti-static precautions throughout.

Step 1: is it actually broken?

An unusual number of Series 7 and netBook "faults" are the machine working as designed. Check this table before opening anything.

Things that are not faults

Behaviour	Explanation
The screen is noticeably dimmer for about 20 seconds after switching on	Normal warm-up behaviour of the STN panel.
The backlight cannot be turned off	There is no function to do so, "even using System.opx in OPL". The panel is not reflective, so it looks dimmer under bright light rather than better.
The charging LED goes out before the battery is full	By design. The charge LED extinguishes at about 70 % capacity; a full charge takes up to 3 hours. A pack that "won't charge fully" is very often this.
The green LED is on whenever the mains adapter is connected	Normal. Charging is shown by the green LED turning yellow and the red LED to its left glowing; the red LED dims as charging proceeds, then goes out and the yellow returns to green.
The machine cuts out suddenly with no warning dimming	Li-ion machines are designed to stop well before the cells are exhausted. The display does not fade as the battery drains — the machine simply stops.
Runtime halves at full brightness	Expect roughly a 50 % reduction, and it probably shortens panel life too.
A CompactFlash card rattles about 6 mm in its drawer	Normal — the play exists to accept Type II devices.
A small hole to the right and front of the keyboard, like a Series 3 reset hole	That is the microphone. The reset hole is under the backup battery hatch.
Old Series 5 Word files are painfully slow to scroll and type in	The Series 7 renders them at Series 5 physical size, leaving a 25 mm gap. Copy the contents into a new Series 7 file and the problem goes.

Step 2: the screen cable — the defining fault

If the display fades, goes patchy, or the touchscreen stops registering taps, suspect the screen cable before anything else. This is the Series 7 and netBook equivalent of the Series 5's ribbon: the cable itself is sound, but the clamp connector on the motherboard loses grip.

Psion's own support answer:

This is quite a common problem with Psion Series 7s and netBooks. Your screen cable is loose and (in the worst case) may need replacing. One quick fix is to press firmly on the 'netBook' (or 'Series 7') logo, above the keyboard. This is often enough to reseat the cable and restore a solid connection for a while. If this doesn't work, you'll need to partially disassemble your machine to get to the screen cable... you remove the logo label between the keyboard and display, then remove the only screw that you'll see. Lift off the top and then extract the pins that hold the screen. When you get to the screen cable, a semi-permanent repair is to insert a wedge of cardboard between the cable and the base of the unit.

The community reached the same place independently, and considered it close to inevitable: "Yes, I think it is inevitable — EXCEPT for Psion's last batch of Netbooks, which had their third or fourth attempt at fixing the screen cable problem (which seemingly actually worked)."

The repair

Read the whole procedure before starting. One step in it can destroy the machine.

1. Remove all batteries — main pack, backup cell, the personality/ROM module and any memory expansion.
2. Warm the badge sticker with a hairdryer for about 15 seconds and peel it off. Cover the keyboard with paper or card while you do this, or you will lift the key legends too. If it does not come away easily, warm it again.
3. Remove the single screw underneath the sticker.
4. With the screen in its half-open position, remove the hinge pins beside the ROM/memory card slots.
5. Lift away the plastic strip carrying the badge, the on/off button and the stylus button. It takes some force; do not crack it.
6. Deal with the screen connector. There are different connector designs; some need two screws removed first. Note exactly how the cable sat before you disturb it.
7. ⚠️ Lift the white clamp very carefully. This is the step that ends machines: "The white thingy that actually holds the cable onto the motherboard should be carefully lifted up. If you put too much force on it and you break it, the motherboard is a total loss."
8. Shim and reseat. Psion's own advice is a wedge of cardboard between the cable and the base. The community variant is a piece of paper laid parallel with the cable under the clamp, with the same piece continuing under the two-screw cover.
9. Support the lid while you refit the screws. One owner's repair failed because the machine was lying flat and the cable slipped out as the screws went back; putting a book under the screen fixed it.

Making it last

Vibration is implicated. One owner traced repeat failures to carrying the machine in a rucksack pocket that rested against a bicycle frame; moving it to a front pocket stopped the recurrence.

The cable design is not the problem — the clamp is, and the clamp cannot be replaced without working on the motherboard itself.

Step 3: removing the battery can wipe the machine

This is the most destructive documented fault on the Series 7, and it is not obvious.

A microswitch in the battery lock mechanism is meant to switch the machine off when you slide the catch to release the pack, leaving the backup cell to hold RAM. On some machines it turns the backlight on instead. The screen lights but stays black, the system never shuts down, and when the pack comes out the surge is more than the 3 V backup cell can carry. The machine cold-boots and the entire internal disk — data, applications and settings — is gone.

The safe procedure:

1. Slide the catch back and look at the screen.
2. If it appears to power up but stays black, hold the catch open with one hand and switch the machine off with the other.
3. Only then slide the pack out.

Worse, one of the rubber feet sits on the underside of the battery catch. Sliding the machine across a table, or carrying it loose in a bag, has been enough to pull the catch open and reset the machine.

Step 4: the build 756 patch can destroy the machine

Psion did release an operating system update for the Series 7. It shipped as the Series 7 Patch (Build version 756) - three files, UPDATE.EXE, Rom_4mb.img and a readme, branded Psion Enterprise Computing and dated 2000. The contemporary community position, repeated ever since, was that no Series 7 update would ever exist.

It also destroys a machine whose Vpp rail has aged, and it gives no warning that it is about to.

What the patch does

The machine must already be on build 750 or greater. Both files are copied to the root of C:, the machine is run from the mains, and UPDATE.EXE is tapped. The screen goes black, the update runs, and a green PASS screen should follow.

Psion's own warning occupies most of the readme:

KEEP THE UNIT POWERED UP FROM THE MAINS, USING THE ADAPTOR, THROUGHOUT THE UPDATING PROCESS!! ANY INTERRUPTION TO THE POWER COULD LEAD TO AN UNUSABLE MACHINE!

The last instruction reads like housekeeping and is not. After PASS, the readme requires the DC jack, the main battery and the backup lithium cell all to be removed, and only then the main battery refitted to reboot. There are two reasons for it. UPDATE.EXE ends in a deliberate infinite loop after printing either PASS or FAIL and never returns to EPOC, so the machine sits there until power is cut. It also issues no Read Array command to the Flash at any point in the binary, so the devices are left in status or identifier mode rather than returning ROM contents, and only losing power resets them.

A blank or white screen straight after running the patch is expected, not a fault in itself. Remove all three power sources before concluding anything.

How it fails

Programming Flash needs Vpp, the programming voltage, and on these machines it is generated on the board from the DC input. That is why the patch insists on mains power.

UPDATE.EXE switches Vpp on and then checks it bank by bank, by reading each device's status register. The check is static: it confirms the rail is present at that instant, with no erase current being drawn. Two outcomes follow, and the message on screen tells you which one you got. The distinction decides whether the machine still works.

Reading the patch failure message

Message on screen	What happened	State of the machine
Vpp not found for all banks	The static check failed. The updater returned before issuing any erase or program command.	Undamaged. The ROM was never written to and the machine still boots. Do not retry - fix the rail first.
ERASE FAILURE 'Vpp not enabled', or Bank x at y command failed	The static check passed, the erase was commanded, and the rail collapsed under load. The device aborted with its Vpp-low status bit set.	Blocks have already been erased. The operating system is gone and the machine will not boot again.

The second case is the trap. A Vpp supply that measures correctly at rest and sags the moment real erase current is drawn passes the check and then fails the operation, and by the time the failure is printed the erase has been under way. Erasing proceeds bank by bank, so a failure partway through still leaves erased blocks behind.

What a failed patch leaves behind

• Backlight on, panel uniformly white, no image.
• No beep on a hard reset, where a healthy machine beeps once and shows the logo for about ten seconds.
• The reset button blanks the screen; the machine returns straight to white.
• Identical behaviour with the ROM card removed altogether.
• On a scope or logic analyser, the ROM address lines sweep continuously at power-on.

The sweep is the diagnostic one. Erased NOR Flash reads as 0xFFFFFFFF, which on the ARMv4 architecture of the StrongARM SA-1100 is condition code NV: the word is fetched and never executed. The core walks the whole address space, wraps and repeats. A free-running address bus with no beep and no display is a core fetching from blank or undriven memory.

Identical behaviour with the card out is not proof the ROM is dead. A CPU that never runs, and a card not making contact, produce exactly the same picture. Clean the card edge with IPA and reseat it firmly before going further.

Recovery

There is no software route out. The SA-1100 has no internal boot ROM; it fetches its first instruction from the Flash and there is nothing else to fall back on. A Series 7 cannot be made to boot from CompactFlash the way a netBook does, because the netBook's card-loading bootloader is itself code held in that machine's own personality module. Erase a netBook's module and it is equally dead. The serial loader inside UPDATE.EXE is no help either: it is part of an EPOC executable and needs a booted operating system to run it.

The module has to be replaced or reprogrammed.

• Replace it. Psionex list pre-programmed Series 7 personality modules in builds 751, 754 and 756. This is the only route with a known outcome, and it delivers the 756 update as a side effect. Check which ROM size your machine takes before ordering: the patch ships a 4 MB image and UPDATE.EXE enumerates 2 MB, 4 MB and 12 MB device configurations, refusing to proceed on anything it does not recognise, which does not obviously square with the 16 MB commonly quoted for the ROM card.
• Reprogram it. No published method exists. Edward Hasbrouck records that reflashing a module with another machine's image "may be possible" but that David Lowe, about as deep into this hardware as anyone, "doesn't know how to flash upgrade the ROM on the personality modules". Anyone attempting it is working without a guide. Note that Rom_4mb.img carries a 256-byte EPOCARM ROM header in front of the 4 MB payload, which an external programmer does not want.

Do not run the patch again on a machine that has already failed it. The rail that collapsed will collapse again, and it will take a replacement module with it.

Symptom table

Psion Series 7 and netBook — fault symptoms

Symptom	Likely cause	Action
Display fades, goes patchy, or needs pressure on the badge to look right	Screen cable loose in its motherboard clamp	Press the badge for a temporary cure; then shim the cable. See above.
Touchscreen ignores the stylus or drifts, and recalibration does not help	Same cable fault — or, on build 754, an OS bug	Try the badge press first. If that fails, soft reset via the hole under the backup battery hatch. The OS bug was cured in build 756 (early 2000). Psion did release a Series 7 patch to that build, but applying it carries the risk in Step 4.
Internal disk wiped after changing the battery	Battery-catch microswitch lighting the backlight instead of powering down	See above. Not recoverable after the fact — this is a procedure to adopt, not a repair.
Machine resets itself in a bag or when slid across a desk	The rubber foot on the battery catch dragging the catch open	Same fault. Check the catch and the foot.
Machine gradually slows until everything crawls; applications start but draw nothing	Build 754 OS fault	Soft reset. "This problem doesn't seem to happen with the later '756' build."
"Disk not present" for the D: drive, or a card that vanishes mid-write	CompactFlash drawer — the plastic stops do not push the card onto the contacts firmly enough on some machines	Shim behind the card with a small piece of card as you close the drawer. Do not use anything thick, and make sure it cannot come loose inside.
PC Card modem unrecognised, or connects only at low speed	Current draw, and Psion published the number: the Series 7 slot is limited to 200 mA, against 800 mA on a late netBook. V90 cards are the worst offenders — including Psion's own Gold cards	Force V34: set the modem Data Init string to AT+MS=11 in the Control Panel. Winmodems will never work — they need Windows.
PC Card works in a netBook but not this Series 7	Expected, and not fixable. A Series 7 slot supplies 200 mA; a netBook built from September 2002 supplies 800 mA, and one built before it 300 mA	Nothing to repair. Note that Psion's September 2002 board change and the independently-reported revision 10, week 35 of 2002 are the same event.
Microphone records nothing, or works intermittently	The microphone connection is a press fit and tends to fail	"Pressing down very hard on the case above the microphone (near right hand shift key) will often cure it for a while."
Serial port dead after using a serial mouse	A serial mouse draws its power from the port. One report describes burning out the port on a Psion this way; the mouse worked right up to the moment it did	Do not power a mouse from the port. Use a self-powered device or a PC Card serial port.
External serial device will not talk to the machine	Not a fault. The Psion serial cable is a null-modem cable	Add a null-modem adapter to "un-null" it when connecting a modem or GPS.
Control Panel soft resets the machine when Add/Remove is opened	A stray non-SIS file in the install folder	Go to *:\System\Install\ and delete or move any file that does not carry the installer icon.
Blank screen but the machine seems to be on	Screen cable, or contrast/brightness at an extreme	Badge press first, then brightness, then disassembly.
Machine will not switch on at all	Flat pack; pack not seated; failed pack	Fit the mains adapter and try again. The pack is not user-serviceable as designed — see Psion Series 7 Battery Service.
Ran the official 756 patch; machine now shows a lit white screen and never beeps	The ROM was erased by a failed Flash programming cycle - the Vpp rail passed the updater's static check and collapsed under erase load	Not recoverable in software. The personality module must be replaced or reprogrammed. See Step 4.
Patch stops with Vpp not found for all banks	The board's Vpp generation is not coming up at all	Nothing was erased and the machine still works. Stop there. Retrying risks the case above.
Corrosion in the backup cell compartment	Leaked coin cell	Neutralise and clean. See Battery Explosion, Capacitor or Corrosion Damage.

Resets

Both procedures use the reset hole under the backup battery hatch.

Reset	Procedure	What survives
Soft	Insert an unfolded paperclip gently until you feel a small click. Turn the machine on without touching any keys as it reboots.	Saved data survives. Changes to open files are lost, and some display, keyboard and Extras-bar settings revert.
Hard	With the machine on, insert the paperclip until the screen turns off. Then hold down both Shift keys as you turn it on. A single beep, then the logo for about 10 seconds, then the demo files.	Nothing. The internal disk is wiped. The Series 7 manual is wrong when it says a hard reset requires removing all batteries for a period — the Shift method works and is far less trouble.

What is realistically repairable

Part	Repairable?	Notes
Screen cable seating	Yes	The highest-value repair on the machine, and Psion documented the fix themselves.
Screen cable clamp	No, practically	Soldered to the motherboard. Breaking it while lifting it means a donor board.
Battery pack	Yes	Rebuildable with new 18650 cells. See Psion netBook Battery Service.
Backup cell	Yes	Standard CR2032, still widely stocked.
Keyboard	Yes	New-old-stock Series 7 / netBook keyboards are still sold in several layouts under part numbers of the form S7_KBD-UK, -US, -DE, -FR, -ES and -NO. The keyboard itself is a sealed unit and should not be further disassembled.
Microphone contact	Yes	A press fit that can be reseated.
RAM (board-level)	For SMD-capable hands	Two unfitted DRAM sites exist. Use low-power parts — the DRAM is powered continuously.
ROM / personality module	Yes, by swapping	A user-replaceable ROM board carrying the bootloader and OS. Pre-programmed Series 7 modules in builds 751, 754 and 756 are still sold. Reflashing one outside the machine is undocumented. See Psion Series 7 for what changes and the direction that is safe.
LCD panel	Donor only	No source of replacement panels is known.
NEC ASIC, Philips CPLD	No	Custom parts. A failure means a donor board.

Psion Digital ceased all repair activity for the legacy range on 1 June 2005. A commercial repair service for the Series 7 still exists at Psionex in Lincoln.

Capacitors

These machines are not recap candidates, and nobody has ever reported one needing it.

A search of the surviving Series 7 and netBook community record — the Series 7 FAQ's own hardware fault list, PsionWiki, the OpenPsion HOWTO, comp.sys.psion, HPC:Factor and the modern collector write-ups — turns up no report of a failed capacitor, a bulging or leaking electrolytic, or anyone recapping one of these machines. The four hardware faults the community actually documents are the screen cable, the battery-catch microswitch, the CompactFlash drawer and PC Card current draw, and none of them is a capacitor.

That is why no capacitor replacement guide is listed for the Series 7, netBook or netBook Pro on Category:Psion. Capacitor work on one of these is justified only by evidence in front of you — corrosion damage from a leaked cell, or a tantalum that has failed short, which presents as a dead machine drawing heavy current the instant power is applied. For method in those two cases, the equivalent section of the Psion Series 5mx Capacitor Replacement Guide covers a comparable low-voltage surface-mount board. For recognising a genuinely failed capacitor when you do meet one, see Capacitor Failure Symptoms.

Related pages

• Psion Series 7 · Psion Series 7 General Maintenance · Psion Series 7 Battery Service
• Psion netBook Troubleshooting Guide · Psion netBook Pro Troubleshooting Guide
• Battery Explosion, Capacitor or Corrosion Damage · Recommended Tools