Editing Psion Siena Troubleshooting Guide

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[[File:Psion Siena.jpg|thumb|420px|A Siena. Half of what people report as faults on this machine are deliberate omissions — no SSD bays, no power socket, no sound recording, no backlight.]]

Fault-finding for the '''[[Psion Siena]]''' (1996).

The Siena is a SIBO machine, so '''the four power states and the supply rail chart in the [[Psion Series 3a Troubleshooting Guide]] apply here too'''.<ref name="sibo">Psion PLC, ''SIBO Hardware Reference'', version 2.10, 3 February 1995, in the [https://doc.psion.info/books/the-psion-sibo-software-development-kit/page/hardware-reference Psion Documentation Project]. Source for the SIBO architecture, the four power states, the supply rails, the keyboard matrix scanning and the NMI sources.</ref> What does '''not''' apply is anything to do with the Series 3 case: the Siena has no button bar, no four-hinge clamshell and no internal SSD bays, so those faults simply do not exist on it.

== ⚠️ Before you start ==

* '''Back up through the serial port first.''' It is the only route in or out of the machine, and diagnosis means removing batteries.
* '''There is no external power socket''', so you cannot keep the machine alive from an adapter while you work. The CR1620 backup cell is all you have.<ref name="wpsiena">[https://en.wikipedia.org/wiki/Psion_Siena "Psion Siena"], Wikipedia. Source for the battery arrangement, the CR1620 backup cell, the absence of an external power socket and of internal SSD bays, the external drive option, the screen resolution and the binary compatibility note.</ref>
* Anti-static precautions throughout.

== Step 1: rule out the things that are not faults ==

'''A large share of reported Siena "faults" are design decisions.'''

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Not faults'''<ref name="wpsiena" /><ref name="spec">[https://www.psion.netogram.com/psionspecifications.html "Psion specifications"], netogram.com. Source for the Siena's sound hardware, screen resolution, keyboard layout, serial speed and expansion arrangement.</ref>
! Reported as !! Assessment
|-
| '''No SSD slots anywhere on the machine''' || '''Correct.''' The Siena has no internal bays. Storage expansion is an '''external SSD or PC-Card drive on the serial port'''.
|-
| '''Nowhere to plug in a mains adapter''' || '''Correct.''' There is no external power input at all.
|-
| '''Will not record sound''' || '''Correct.''' The Siena has a '''piezoelectric beeper''' only — no microphone, no CODEC. Recording is a Series 3a/3c feature.
|-
| '''Screen is dim in poor light''' || '''Correct.''' No backlight was ever fitted.
|-
| '''Series 3 software misbehaves or will not fit''' || '''Expected.''' The Siena is binary compatible with the Series 3, but many programs needed modification for the '''smaller screen (240 × 160) and smaller memory'''.
|-
| '''A Series 3 or 3a serial cable will not fit''' || '''Expected.''' The Siena connector matches the '''[[Psion Series 3c|3c]]'''.<ref name="wp3">[https://en.wikipedia.org/wiki/Psion_Series_3 "Psion Series 3"], Wikipedia. Source for the statement that the 3c serial port was changed to match the Siena's.</ref>
|}

== Step 2: power ==

With no mains input, '''every intermittent fault on a Siena is a power fault until proved otherwise'''.

{| class="wikitable styled-table" style="width:100%; text-align:left;"
! Symptom !! Cause !! Action
|-
| '''Will not switch on''' || Flat or poorly-contacting AAA cells; machine held in the SIBO '''backup state''' because the main supply is not reaching the board || Fit known-good alkaline AAAs and check them '''under load'''. Clean the contacts in the compartment under the detachable top casing.
|-
| '''Loses data on every battery change''' || '''Flat or badly-contacting CR1620.''' On a Siena there is no adapter to fall back on, so a weak backup cell loses everything || Replace the CR1620 and check the contact pressure.
|-
| '''Runs down cells quickly''' || AAA cells hold roughly a third of an AA's energy — the Siena is simply working from less || Compare against a fresh set before assuming a fault. If the drain is genuinely abnormal, check for a shorted or leaky cell contact.
|-
| '''Corrosion in the battery compartment''' || Leaked AAA cell || Neutralise and clean. In a case this small the electrolyte has very little distance to travel. See [[Battery Explosion, Capacitor or Corrosion Damage]].
|}

== Step 3: the serial port ==

'''If the serial port does not work, the machine is effectively sealed.'''

{| class="wikitable styled-table" style="width:100%; text-align:left;"
! Symptom !! Cause !! Action
|-
| '''No PC connection''' || Wrong cable; dirty connector; baud rate mismatch || Confirm you have a '''3c/Siena''' cable. Clean the connector. The Siena serial runs at '''19,200 bit/s'''.<ref name="spec" />
|-
| '''External SSD or PC-Card drive not recognised''' || Cable, connector, or the drive itself || The Siena drives external storage over the same serial link, so a serial fault and a storage fault look identical. Test the link with a PC first.<ref name="wpsiena" />
|-
| '''Infrared transfers fail''' || Dirty or scratched IR window; misalignment || The IR port sits next to the serial port. Clean it; IR needs line of sight at both ends.<ref name="wpsiena" />
|}

== Step 4: display and keyboard ==

{| class="wikitable styled-table" style="width:100%; text-align:left;"
! Symptom !! Cause !! Action
|-
| '''Display blank, machine otherwise alive''' || Contrast out of range, or the '''Vcc3 / Vee1''' rails || Adjust contrast in software first. On SIBO machines '''contrast is a software-controlled DAC''' driving the negative Vee1 rail — there is no wheel to turn, so if the software control does nothing the rail has failed.<ref name="sibo" />
|-
| '''Display scrambled or badly timed''' || LCD controller or its timing, with Vcc3 healthy || A board-level fault.
|-
| '''Whole keyboard dead''' || Keyboard scanning || The matrix is scanned by driving each column in turn and reading the rows, so a whole dead keyboard points at the scanning path rather than at the keys.<ref name="sibo" />
|-
| '''A row or column of keys dead''' || One matrix line || Trace that line.<ref name="sibo" />
|-
| '''Keys need a hard press''' || Dirty membrane or pads || Wash the membrane, clean the pads. See [[Psion Siena General Maintenance]].
|-
| '''Numeric keypad dead, main keyboard fine''' || Its own matrix lines || The Siena's numeric keypad beside the screen is part of the same matrix; treat it as another block of rows and columns.<ref name="spec" />
|}

== Step 5: the shared SIBO material ==

For the '''four power states''' (standby, backup, idle, operating), the '''supply rail chart''' and the watchdog behaviour, see '''[[Psion Series 3a Troubleshooting Guide]]'''. The Siena runs the same '''V30H at 7.68 MHz''' and the same architecture.<ref name="wpsiena" />

One rail note specific to this machine: the '''+16 V Vh''' Flash programming rail exists to serve SSD slots, and the Siena has none internally. If you are using an external drive and Flash packs read but will not format, the fault is in the '''external drive''', not in the Siena.<ref name="sibo" /><ref name="wpsiena" />

== What is realistically repairable ==

{| class="wikitable styled-table" style="width:100%; text-align:left;"
! Part !! Repairable? !! Notes
|-
| Battery contacts and compartment || '''Yes''' || The commonest real fault.
|-
| Serial connector || Yes || Worth the effort — it is the only route in or out.
|-
| Keyboard membrane || Yes || Washable.
|-
| LCD panel || With a donor || Siena-specific 240 × 160 panel; nothing else in the range fits.
|-
| Mainboard || Board-level swap only || Dense surface-mount SIBO construction.
|-
| ASIC || '''No''' || Psion custom silicon.
|}

== Related pages ==

* [[Psion Siena]] · [[Psion Siena General Maintenance]]
* [[Psion Series 3a Troubleshooting Guide]] — the shared SIBO diagnostics
* [[Battery Explosion, Capacitor or Corrosion Damage]] · [[Recommended Tools]]

== References ==

<references />

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[[Category:Psion]]
[[Category:Troubleshooting Guides]]