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Old 04-11-2006, 11:35   #14
tvout
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Re: pc - determining cause of death

Quote:
Originally Posted by AntiSilence View Post
Not strictly true. The PSU provides more than 1 supply rail... For example, there's a +5V rail, a +12V rail, and some other (including some negative rails, like -12V).

Each rail supplied power to different parts of the PC. The +12V rail, for example, supplies HDD's and GFX cards etc. If only part of a PSU has blown, the rest may work. EG, the +5 rail may still work.

PC power supplies are switched mode, and are really nasty beasts to fault find on, since all outputs only work correctly under load. Nasty.
Spot on. That would explain it. The only activity on the motherboard was a DIMMLED', DIMMs require 5v usually (well I know some are different) don't they? They also said that the monitor had power (on pass through). I used the tester on the 4 pin molex connectors to the HD/CDROMs etc and they didn't indicate any power at all on the tester.
As I say the only led that lit from the PSU to the motherboard connector was the +5V one, suggesting that 12v etc. rails in the PSU had blown.
When I spoke to the witnesses :o), well, owners they said they hadn't heard the fan start up the last few days...
At a guess could the fan have been the PSU one, being thermo-controlled and this not starting up led the PSU to overheat and cause damage?

Does this all sound feasible?
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