Help with Strange Power-on Problem

[waterlovertx]

I built a system based on the Gigabyte GA-MA785GPMT-UD2H motherboard and an AMD Phenom II processor. All worked fine for several weeks. One day while my wife was using it she said it got very slow and then just died. It would not power back up. I put in a new power supply but it still will not power up. Sometimes the LED fires briefly when I turn the power on, but nothing else happens. I considered whether it could be a power switch issue like a short of some sort. But this seems unlikely given it has been working for a while and the problem happened when it was already running.

At this point it seems that it is likely the MB or CPU. I overclocked the internal graphics clock a great deal so I am thinking changing the CPU is the next logical step. But, I'll have to buy another one to try it and being an engineer, going at this in a purely trial and error fashion doesn't sit well.

Any suggestion?

What are the symptoms in a dead CPU system? Does it sound like what I'm seeing?

Thanks in advance for sharing your expertise.

 

[idejason]

Is the PSU new or re-used from a previous system, If so how old?

 

[Outlander_04]

strip the system .

leave one stick f ram , and the cpu and see if it will POST


make sure there is a mb speaker attached so you can hear the beep

If you have clocked the 785 igp you may have fried the nb chipset , and will need to replace the motherboard , but the only way to know is start from scratch

 

[waterlovertx]

Is the PSU new or re-used from a previous system, If so how old?

The original power supply was a few weeks old. The one I swapped in to test was a brand new Antec supply.

 

[waterlovertx]

strip the system .

leave one stick f ram , and the cpu and see if it will POST


make sure there is a mb speaker attached so you can hear the beep

If you have clocked the 785 igp you may have fried the nb chipset , and will need to replace the motherboard , but the only way to know is start from scratch

- I've disconnected everything and nothing but a flash of light when I first hit power. I suspect it's either the MB or the processor, but wish I could narrow it down and only re-order one. But I don't have anything to test these independently.

 

[aford10]

Try it with the motherboard outside the case, on a piece of cardboard. Tie up loose cables. This will rule out some sort of short.

Double check and make sure the PSU switch is turned on.

 

[waterlovertx]

Try it with the motherboard outside the case, on a piece of cardboard. Tie up loose cables. This will rule out some sort of short.

Double check and make sure the PSU switch is turned on.

I did this to make sure, just in case, but the system had been running and stable when this happened. Didn't change the symptoms. I think it must be the MB and will order one soon if I can't think of anything else. Thanks for the insight.

 

[aford10]

Motherboards fail more often than CPUs, so that's probably a good place to start.