Dead PC : How to tell if PSU or Mobo

Ergates

Ergates

Ergates

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Joined
24 Jun 2005
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264
PC was working fine last night, dead today. Absolutely no response from the power switch. No lights on the Mobo inside.

The mouse *was* lit up initially, but now isn't - not sure when it died as I was scrabbling around under the desk, possibly when I removed the CMOS battery. Not sure what that means.

First thought would be PSU - however there is an LED lit up on the GFX card, so it's clearly not totally dead. So it might be the Mobo.

Other than just biting the bullet and buying a replacement for one or the other, are there any tricks to working out which is dead? [I don't have access to anyone else PC to borrow bits from]
 
Jam a paperclip into the power connector.... OK.

If I die from this I'm coming to haunt you.

Update: PSU fan didn't start when I tried that, so I'm hoping it's the PSU.

I'm also hoping that as it has modular cabling I can just get another one the same and just swap the PSU itself leaving all the cables in place.

Ta.
 
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Ergates said:
I'm also hoping that as it has modular cabling I can just get another one the same and just swap the PSU itself leaving all the cables in place.
Click to expand...

Please DON'T re-use the modular cables from one PSU to another, you could permanently damage components this way! General rule of thumb is modular cables from one PSU are NOT interchangeable with another PSU. Even PSUs from the same manufacturer can have different modular cable pinouts.

If you ever intend to re-use cables from one modular PSU to another, please triple/quadruple check the cable pinouts are identical!
 
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Ergates said:
I'm also hoping that as it has modular cabling I can just get another one the same and just swap the PSU itself leaving all the cables in place.
Click to expand...

What make and model psu is it? As stated above, it can be a bad and expensive idea to use cables other than those that came with the psu. Some manufacturers such as Corsair have had multiple variants of the same model psu, sometimes even switching manufacturers, and there is no guarantee that the pin outs are the same from one version to another.
 
drakulton said:
https://www.wikihow.com/Check-a-Power-Supply

This might start you in the right direction. If the PSU powers up them it could be the mobo.
Click to expand...
Picture showing which contacts to short is using ancient 20 pin connector.
So really not that good guide.
https://www.silverstonetek.com/downloads/QA/PSU/PSU-Paper Clip-EN.pdf

Heck, whole pin counting issue could be avoided if someone just grabbed marketroids from tie and properly tightened it.
While explaining in R. Lee Ermey voise that from now on they have to get permission for doing anything.
With good old colour coded wires it would be simple to find green wire and connect that pin to ground wire.
 
You would have to be pretty inventive to kill yourself with ATX PSU's output voltages...
Even licking exposed wiring wouldn't really be more dangerous than doing that for terminals of 9V battery.


Bitfenix has very few PSUs and haven't heard there being any variants of those.
So other Whisper M should be safe for same cables.
Assuming you want to stay in those.

Though I don't think any of those PSUs can be older than its 5 year warranty.
So if PSU doesn't start, it should be warranty case.
 
Yep the bridging of green + black to power the psu on as a test pretty much only tells you the psu powers on but nothing more. Could have further issues when under load so really the only viable test is to swap out the psu completely for a known good unit.
 
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