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Generally Speaking (bad mobo Q)

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#1 dontknowitall


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Posted 20 May 2011 - 12:35 PM


This is a general question that I would like to be applied towards mobos/cpus in general.

The PC does not power on, but the MOBO lights the green power light.
The PSU tests OK in a tester and powers on by itself.
Another power switch form another case is tested, and it still doesn't turn on.

It is safe to assume a bad MOBO, correct? Does the CPU need to be functional for the fans to spin and the thing to power on?

Is there anyway to know for sure (without another CPU) that it's not the CPU??

Thank you.

Edited by dontknowitall, 20 May 2011 - 12:41 PM.

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#2 MrBruce1959


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Posted 20 May 2011 - 01:45 PM

Does the CPU need to be functional for the fans to spin and the thing to power on?

No, you would simply get a system beep code referring to a processor related error, but the cooling fans would still spin up and power would still flow into the motherboard.

The motherboard can be bad, specially in the area of the CPU, but it is rather rare to have a CPU go bad without any noticeable damage during the inspection of it, so if it is at all related to the CPU check the motherboard closely in that area.

Check the CPU slot for any signs of failure, scored or burned areas.

Have you checked those electrolytic capacitors for any signs of leakage or blown seals?

Check the ones with the purple outer coating, those are a brand of capacitors that are notorious for failure.

Check for any loose connections, short circuits or disconnected wires.

You might even try doing a process of elimination, by disconnecting one piece of hardware at a time and testing the system to see if elimination a piece of hardware actually causes the system to start up normally.

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#3 dontknowitall

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Posted 20 May 2011 - 02:18 PM

All of the CAPS look good.. no buldges or leaks.

I've checked the wires and a different PSU.

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