I cleaned a Pc, and now it goes on a boot up, shut down loop.

[Geettttt]

So I cleaned my dad's old Pc, I removed the case fan cleaned it and air sprayed the rest of the Pc. Then I removed the stock CPU cooler, cleaned its heatsink with a toothbrush and air sprayed the fan. Put it back together, then I cleaned off the dried thermal paste off the cooler and the CPU using rubbing alcohol, waited for it to dry and wiped it with a paper towel piece. Then Added new thermal paste onto the CPU and reinstalled the cooler onto the MB. But after I put it all back, and tried to turn it on the PC would boot up and shutdown in a continuous loop.

I checked and the fans are running, all the wires don't look loose, pretty sure that there is no paste on the MB, the cooler is tightly secured. I did disconnect the PSU wire and everything was turned off while cleaning. Did I do something wrong? If so how can I fix it? Would resetting the BIOS or CMOS help or would I have to bench it to see if it works...

 

[USAFRet]

This is a physical problem, not the BIOS or the CMOS.
All you did was take it apart and put it back together. That would not mess up the BIOS.

Check ALL of the cables again. Not just look, but actually touch and verify.

 

[drkatz42]

Double check all PSU, HD etc connections to the MB. Make sure the GPU is firmly seated and if it has a power connection, make sure it's tight. Go ahead and clear the CMOS and give it a go.

 

[Geettttt]

Double check all PSU, HD etc connections to the MB. Make sure the GPU is firmly seated and if it has a power connection, make sure it's tight. Go ahead and clear the CMOS and give it a go.

The PC is from 2011 and it doesn't have a GPU. Also the guy above you said this was a physical problem, so should I still reset it?

 

[joo_x]

I think some of the rams are lossy try to run the computer with 1 stick ram

 

[Geettttt]

This is a physical problem, not the BIOS or the CMOS.
All you did was take it apart and put it back together. That would not mess up the BIOS.

Check ALL of the cables again. Not just look, but actually touch and verify.

I check all the wires and they are in place...

 

[Geettttt]

I think some of the rams are lossy try to run the computer with 1 stick ram

The PC was working right before the cleaning, but I only air sprayed the cans, so what are the chances that it the ram and not something else?

 

[drkatz42]

Double check all PSU, HD etc connections to the MB. Make sure the GPU is firmly seated and if it has a power connection, make sure it's tight. Go ahead and clear the CMOS and give it a go.

The PC is from 2011 and it doesn't have a GPU. Also the guy above you said this was a physical problem, so should I still reset it?

Clearing the CMOS will do no harm. Over my years of building, cleaning and repairing for myself, this has worked on occasion when nothing else would.

 

[Geettttt]

Double check all PSU, HD etc connections to the MB. Make sure the GPU is firmly seated and if it has a power connection, make sure it's tight. Go ahead and clear the CMOS and give it a go.

The PC is from 2011 and it doesn't have a GPU. Also the guy above you said this was a physical problem, so should I still reset it?

Clearing the CMOS will do no harm. Over my years of building, cleaning and repairing for myself, this has worked on occasion when nothing else would.

Thx, because my dad PC was old, all I had to do was replace the Cmos Battery and it worked.