Computer fails to reach post

I am trying to help a friend with their computer that fails to post. It doesn't seem to get to post, and you can't see the bios screen or anything. The computer continues to power cycle. Fans spin up, you might hear a sound from the optical drive or hdd and then it powers down and then repeats. I have used a PSU tester on their power supply to confirm proper voltages and tried a known working proper PSU and it sill does it. There does not seem to be any visible issues with the motherboard but I suspect that it's power regulation on board is failing. I pulled the board to make sure standoffs are in the correct places and the board does not seem to be having grounding issues.Thoughts?

i would say first reseat the cpu. best way is to takeout the mobo from the case, lay it on its box, install the cpu and cpu fan, install 1 ram stick in slot 1, install the gpu, connect the psu and fire it up outside the case.

 

I had the same issue just a few months ago and my issue was that the front panel connectors were shorting the motherboard. So I say undo the front panel connectors and use like a key or a screwdriver to bridge the on/off pins and see if it will post.

RAM issue? Try different modules and different slots.

OK, I disconnected all connectors and removed all ram and video card and it continues. It does however boot and run fine out of the case. I tried a different case and it continued to fail. It fails with or without the IO shield and with or without any/all front panel connectors or addons...my next step is to try to isolate the back plate on the board and see if that is the culprit.