RetroTechCollection

Psion Revo Plus Troubleshooting Guide

Fault-finding for the Psion Revo Plus (and the Diamond Mako).

A Revo beside an Ericsson MC218. Diagnosing a Revo Plus is diagnosing a Revo — with one fault crossed off the list.

The Revo Plus is a Revo with 16 MB of RAM, a larger battery and the loose-battery problem fixed.[1]

The whole of Psion Revo Troubleshooting Guide applies here — the battery and charging table, the case microswitch, the screen and connectivity faults, the list of deliberate omissions and the backlight story. This page records what differs.

One fault you can cross off

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Original Revos suffer from batteries coming loose and unplugging inside the case, producing intermittent deaths, unexplained resets and a machine that will not charge. Psion fixed this on the Revo Plus.[1]

So on a Plus:

  • An intermittent death or a refusal to charge points at the cells or the charging circuit, not at a loose connector.
  • You do not need to glue the battery connector as a preventive measure — that is a Revo recommendation.
  • If the connector genuinely is loose on a Plus, something else has disturbed it — most likely a previous repair.

Charging faults

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Identical to the Revo, and the over-80 % rule applies to both models.[1]

Symptom Assessment
Cells get hot; charge never terminates Overcharging. Charge termination senses a thermal change around 80 %. Do not put either Revo model on charge when the battery is already above about 80 %.[1]
Red charging light goes out early Normal. It turns off at around 84 %.[1]
Battery meter obviously wrong Not recalibrated. Hard reset, then charge uninterrupted 0–100 %, preferably switched off, ignoring the meter.[1]
Recalibration charge seems too short Expected on a Plus. It has a larger battery than the Revo, so the six-hour figure quoted for stock Revo capacity is not long enough. Extend it proportionally.[1]
Replaced cells behave oddly Wrong chemistry. NiMH only.[1]
Charges erratically after a cell replacement Damaged or displaced thermistor. It must be intact and held against the cell body.[2]

The case microswitch

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Unchanged from the Revo. A microswitch on the rear switches the machine on and off as the case opens and closes, and it is easily broken by too much force when refitting the battery bay.[2]

A Plus that no longer wakes on opening has very likely lost this switch to a previous battery replacement.

Diamond Mako

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The Diamond Mako is a Revo Plus rebadged by SONICblue for the United States and Canada.[1] Everything here applies to it, and the battery replacement procedure explicitly covers it.[2]

Everything else

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See Psion Revo Troubleshooting Guide for the full battery and charging table, the screen ribbon restraint, the connectivity faults, the deliberate omissions (no backlight, no card slot, smaller screen, non-replaceable cells) and the EL+/EL− backlight investigation.

For the shared EPOC diagnostics — reset levels, the Shift-Ctrl-P Battery Information screen and touchscreen calibration — see Psion Series 5mx Troubleshooting Guide.

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References

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  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 "Psion Revo", Wikipedia. Source for the Revo Plus differences, the fix for the loose-battery problem, the Diamond Mako rebadge, the NiMH-only requirement, the over-80 % charging caution, the recalibration charge and the 84 % charging-light behaviour.
  2. ↑ 2.0 2.1 2.2 David Savery, "Psion Revo/Diamond Mako Disassembly & Battery Replacement", R3UK, 2004. Source for the thermistor, the pack construction, the case microswitch and the disassembly cautions, covering the Revo, Revo Plus and Diamond Mako.


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