Editing Acorn A5000 Troubleshooting Guide (section)

== First: power ==

Most "dead A5000" faults are the PSU or its fuse. Work the Service Manual sequence:<ref name="sm" />

# Switch off, unplug the mains lead. Check the '''5&nbsp;A fuse in the mains plug'''. Fit a new 5&nbsp;A fuse; if it blows on switch-on, the PSU is faulty &mdash; exchange it.
# Measure the rails at the faston power connectors:

<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table" style="width:90%; text-align:center;"
|+'''A5000 supply rails'''
! Rail !! Feeds
|-
| +5&nbsp;V || Main PCB, floppy drive, hard disc
|-
| &minus;5&nbsp;V || Backplane expansion connector
|-
| +12&nbsp;V || Video connector SK1 pin&nbsp;12; floppy/hard-disc motors
|}

# If the PSU runs then cuts out, check the '''fan''' and that the fan aperture is not blocked &mdash; a stalled fan or blocked aperture causes thermal shutdown. Repeated shutdowns mean a faulty PSU.<ref name="sm" />