Luckily, it's not MY PC. My son's PC would not work for some reason last weekend. A cold boot would have the fans whirl to life, then turn off after 5 seconds, then turn back on again. No display on the screen though. Tried a different DVI port on the 5770 GPU, no joy. Tried the HDMI port to my 27" monitor that I know is working, nothing.

Tried an old GPU which I never tried before so not sure if it's working, really, but still, the fans would spool up, but no display.

At this point I'm thinking the mobo is kaput... or the CPU is dead. Either way, I just suspect that it is. Is there any way of verifying where the problems lie? I think at this point I've eliminated the monitor, PSU, and the GPU as culprits, so it's just the CPU, board, and RAM to test.

I'm not really sure how far I want to push it to repair his PC though. I got the CPU/board/RAM second hand from a fellow SimHQ'er and basically, his hardware is older than my already-long-in-the-tooth i5 750 setup. With Black Friday approaching, I might take this opportunity to upgrade my CPU/board/RAM, give him my i5, and win-win! However, I do want to be able to verify that it's one of those components in his setup that is faulty.

Any help appreciated!

Have you tried to change your mobo's battery?

Hmmm... need to find a seller that sells that type of battery....

Well, new battery in and still no joy.

Sorry to hear that. How about switching your RAM with the ones you're using on your own PC; try to clean your CPU cooler as well.

The RAM is old DDR2 unfortunately.

Do you get any BIOS Beeps?? there should be one near first turn on of PC.. I would suspect the PSU..Do you have a PSU Tester?? If not you can get them for like 15bucks or so at computer stores..

No PSU tester... no beeps or anything and if it weren't for the fact that there's no picture on the monitor, the PC hums like it was operating normally.

Well did it beep before or do you know for sure the PC Speaker is connected to the motherboard?? IF so and it did not beep or even post probally dead PC ..

No beeping at all. And yes, the speakers are on and connected.

I know it's probably a pain but can you try to swap the PSU from your system assuming it's compatible? Actually you don't need to go to too much trouble.Take the PSU out of your son's PC and just connect up the bare essentials to yours to see if it will boot.No need even to fit the PSU in place,just connect the power etc.Of course,if you have concerns about connecting a possible 'duff' PSU to your system then you will have to go the other way.

As I understand it,when a PSU starts,it does a self-test to make sure voltages are in spec,once that is confirmed a signal is sent to the CPU so that booting may continue.I once had this massive book about PC repairs that I tried to get through,I remember reading the section on non-start and that sprang to mind.

Things to check:

Motherboard is clear of loose wires or screws causing it to touch the case.

Cables connected to the motherboard are seated properly and in their correct sockets including CPU.

Thermal paste fresh or old between CPU and cooler.

GPU is correctly seated.

RAM: seated properly. Remove one stick and try. Try sticks in different slots.

If you can get to bios, then change RAM timings to whatever is written on the sticks as well as loading default settings.

Thanks for the recommendations! I'll try them as I upgrade my son's PC to see what parts can be salvaged.