PC power supply or power switch

Yesterday (Saturday) we had a six hour power outage when some yahoo took
out a power pole. After power was restored about midnight last night, I
went in early this morning (before church even!) to start up all the
servers and the System i.


Everything came up just fine except the office manager's desktop PC. It's
Win XP and not new by any means. It's hooked to an APC battery backup so
it's always had clean power. The power switch does nothing. I tried
plugging it in to multiple working outlets. I even tried a 2nd power cord,
still nothing.


Initially I suspected the power supply, but in thinking about it at home
this afternoon, it just seems odd that the power supply would go out just
because we lost power. Never had an issue with this desktop before.


I'm wondering if it could be the power switch instead of the power supply.
This PC stays on 24x7. It never gets shut down, just rebooted after Win
updates, so the power switch hasn't been "used" in years. I have nothing
concrete that it's the power switch, just gut feel. Does that seem
reasonable?


I leave for an out of town conference at noon tomorrow, so there isn't much
time to experiment.


Thanks.