Psion Series 3mx Hinge Repair
The Psion Series 3mx (1998) has the four-hinge clamshell of the Series 3 family, and broken hinges are one of the family's documented weak points.[1] The repairs are the same as on the Psion Series 3a, and the full procedure, including separating the lid from the base, is in Psion Series 3a Hinge Repair. On the 3mx the SSD door microswitches must be protected when the main board comes out.
Identifying the broken hinge
[edit | edit source]| Hinge | Location | How it fails | Symptom |
|---|---|---|---|
| Two visible hinges | Just beyond each end of the button bar; metal pin through the centre | The 8 mm neck joining the hinge to the lid shears off about 2 mm above the hinge | Lid loose on that side |
| Two hidden hinges | Plastic pegs between the battery compartment and the button bar | The peg breaks off | Back of the machine sits crooked as it opens; button bar flexes outwards |
Before you start
[edit | edit source]- Back up the internal disk. Never remove the main cells and the CR2025 backup cell together.[3][4]
- Open both SSD doors before lifting the main board. The 3mx senses the doors with a pair of angled microswitches whose plastic tips snap off if the board is prised up with the doors closed, after which the machine does not see SSDs in either slot.[5]
- With the board out, look at both switch tips. If they are already broken, the repair is in the Psion Series 3mx Troubleshooting Guide.
- Work on an earthed mat with a wrist strap, and do not bend the LCD module.[6]
Repair procedure
[edit | edit source]- For a sheared visible hinge, bond the broken piece back with epoxy, with or without a thin steel strip across the joint. David MacKay used both methods and both held.[2]
- For a broken hidden hinge, release the button bar from its springs, drill a small hole through the root of the broken peg and fit a short right-angled piece of spring wire, paper clip or filed nail as a new peg. The hinge spring holds it in place.[2][7]
- If the lid itself is beyond repair, remove the main board (SSD doors open), disconnect the button-bar and LCD cables, remove the button bar and springs, and pull the two hinge pins to separate the halves.
- On reassembly, push the hinge pins fully home so that their heads are flush, refit each hinge spring in its own socket, and test the screen before closing the case.[6]
The detailed steps for each stage are in Psion Series 3a Hinge Repair.
Donor lids
[edit | edit source]Use a lid from another 3mx. Every 3mx is backlit, while only some 3c machines, mainly for the US market, are.[1] The 3mx is silver and the 3c dark grey.[1] Psion's Series 3a manual also warns that LCD modules come in positive-bias and negative-bias versions, and that a negative-bias module fitted to a positive-bias main board is damaged.[6]
Related pages
[edit | edit source]- Psion Series 3mx
- Psion Series 3mx General Maintenance
- Psion Series 3mx Troubleshooting Guide
- Psion Series 3a Hinge Repair
- Psion Series 3c Hinge Repair
- Recommended Tools
References
[edit | edit source]- ↑ 1.0 1.1 1.2 "Psion Series 3", Wikipedia. The four hinges, the documented clamshell problems, the 3mx backlight and silver finish, and the 3c's backlit models.
- ↑ 2.0 2.1 2.2 David MacKay, "Psion 3a Hinge breakages" and "Left Hinge Surgery", Psion 3a Information pages, University of Cambridge. Hinge locations, failure modes and repairs.
- ↑ Psion PLC, Series 3c User Guide, Version 1.0, August 1996, part no. 6103-0107-01. Hosted on this wiki as File:Psion Series 3c User Guide (August 1996).pdf. Changing the batteries (pp. 25–27).
- ↑ "Psion specifications" (Psion 3mx, Psion 5, Psion 5mx, Revo and Revo Plus), netogram.com. Series 3mx backup cell and screen.
- ↑ R. Zealley, "Psion Series 3mx SSD door microswitch repair", Retro Coding, 25 May 2020. The 3mx door microswitches, how they break, and their repair.
- ↑ 6.0 6.1 6.2 Psion PLC, Series 3a Service Manual, Version 1.0, June 1996, part no. 6103-0114-01. Hosted on this wiki as File:Psion Series 3a Service Manual (June 1996).pdf. ESD note, disassembly (pp. 9–13) and reassembly notes (pp. 13–15).
- ↑ Daniel Pfund (ed.), "PSION Series 3/3a palmtop FAQ", part 3/6, v2.6, posted to comp.sys.psion.announce and comp.answers; copy hosted by David MacKay. Section 4.1.9, "Left hinge breaks".