Failed PSU or motherboard?

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Joined
27 Mar 2007
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693
Last night I was forced to turn the PC off at the mains - thought nothing of it.

This morning, it won't boot up at all. No lights are on inside the case and pressing the power on button doesn't result in any activity whatsoever.

Steps I've taken:

1. Reset CMOS
2. Leave the PC unplugged from the mains for 20 mins
3. Leave the PC plugged in but with PSU switch off for some time
4. Tested the power switch header on the MB
5. Paperclip test with DVD drive: PSU fan starts spinning immediately, the light on the drive flashes but pressing the eject button doesn't do anything.
6. Paperclip test with old HDD: PSU fans starts spinning immediately and the HDD starts working right away too
7. Booting up with everything disconnected (just mb and ram) - no movement whatsoever.


Is there any way to tell whether it's the motherboard or the PSU without buying replacements for either?

I am strongly suspecting it's the MB but then the DVD drive I connected doesn't respond to the eject button - could this mean that there is not enough power being supplied?
 
Hey mate, thanks for your reply but did you actually read my post? I did the paperclip test with 2 different devices (I don't have a fan that has a suitable connector though).
 
Sorry got a cold , so if you have hard drive activity then it seems your psu is fine.

Take the motherboard out the case and just connect the bare minimum , one hard drive dvd a single stick of ram.

it could be either the cpu or motherboard.
 
OK mate, will try that now - thanks. If it was the CPU, wouldn't I be at least getting lights on the MB and wouldn't the PSU at least start to spin the fans etc?
 
. If it was the CPU, wouldn't I be at least getting lights on the MB and wouldn't the PSU at least start to spin the fans etc?

Sometimes the cpu can take out the motherboard and vice versa .

Look to see if ther any burn marks around the power connectors on your motherboard.

Whats your motherboard and cpu ?
 
Intel Core i5-3570K 3.40GHz (Ivybridge) Socket LGA1155 Processor (77W) - Retail
Gigabyte Z77-D3H Intel Z77 (Socket 1155) DDR3 Motherboard

Both are a month out of warranty... :(
 
Antec TruePower Trio 550W. It's old but haven't had any problems with it whatsoever.

Just tried running the motherboard outside the case - no luck.
 
You can pass the paperclip test and still have a borked PSU, not much help I know.

Though one question, why did you have to switch the PC off at the mains? If PC locked up etc it could point to a fault on the motherboard? I know the obvious is taking it to a friends and hooking up there PSU? Though a bit of a ball ache I know.
 
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