Computer doesn't boot, doesn't beep

[dopira]

I built a PC a couple of years ago and it was working fine but I wanted to upgrade my video card. I ended up getting a bigger case so that the new card would fit and I also got a new CPU cooler (since the stock one died).

After moving everything to the new case and installing the CPU cooler, my computer does not successfully boot anymore. It powers on for about 5 seconds and all the fans start up. Then it shuts off and tries to boot again like 1 second afterwards. This power on / power off cycle repeats indefinitely.

There is no output on the monitor, no system beep.

I removed all the power except the main motherboard connector and the computer boots and stays on (so I don't think it's a power supply issue). The reset behavior is seen only when the ATX12V is connected.

Any ideas on what might be wrong? Did I destroy my CPU when install the new cooler? Is there something wrong with the motherboard? What experiments can I try to narrow it donw?

 

[Matt1970]

Get down to basics. Just connect the board, processor, 1 stick of ram and your old video card. Also, did the new case mean new power supply as well?

 

[meeshu]

Possibly the PSU is faulty or is being overloaded.

What are the makes and models of CPU, PSU, motherboard, video card, CPU cooler, and memory please? And how many SSD's and HDD's are being used?

 

[ArisVer]

Also check for grounding issues. A good way to is to check the mainboard outside of the case.

 

[silicon]

Also check for grounding issues. A good way to is to check the mainboard outside of the case.

as suggested by arisver check for possibly an extra standoff under the board causing a problem. also remove the board form the case, recheck the fan installation for problems, place the board on a non-conductive surface, and try to see if the board will work.

 

[inachu]

Sometimes those pin jumper leads depending on your motherboard get loose.
Just follow the case power button wiring to the mother board.

In one case may not be the pc but the power button could be bad.

Always work cheap solutions first then work up from there. Power buttons failing is rare but not unheard of.