Editing Osborne Vixen Troubleshooting Guide (section)

== Preliminary & Power-up Checks ==

Begin by confirming the Vixen’s power supply and startup sequence, as many issues stem from simple electrical faults.

=== Visual & Basic Checks ===
* Remove the case top and inspect for burnt components, corrosion, or leaking capacitors.
* Check for loose or oxidised connectors, especially at the power input and disk drives.
* Ensure all ribbon cables are firmly seated.

=== Power Supply & Voltage Checks ===

{| class="wikitable styled-table"
! Test Point !! Expected Voltage !! Notes
|-
| Mainboard +5V rail || +5.0 V DC (±5%) || Logic supply—measure at RAM/CPU Vcc pins
|-
| Mainboard +12V rail || +12 V DC (±10%) || Disk drives, CRT, some logic
|-
| CRT board || +12 V DC, +180 V DC || For video and CRT anode (observe safety)
|-
| Floppy drive connector || +5 V / +12 V DC || Both rails required for operation
|}

* If voltages are low or missing, check the internal fuses and PSU output.
* Inspect for cracked solder joints at the power jack and switch.

=== Power-up Symptoms Table ===

{| class="wikitable styled-table"
! Symptom !! Likely Cause !! Action
|-
| No lights, no fan, no CRT glow || Blown fuse, dead PSU, broken switch || Test/replace fuse, check switch continuity, recap PSU
|-
| Fan runs, CRT dark, no beeps || CRT supply failure, video board fault || Check CRT voltages, inspect video board components
|-
| Power LED on, no disk activity || Logic board not running, CPU/RAM fault || Proceed to logic-level checks, test CPU reset/clock
|}