Computer fans boot for a 1/2 a second, then nothing

faabiian3

Honorable
Oct 12, 2013
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10,530
I won't go into too much detail as I think I bored people with a previous post.

I have a computer I built last year, specs:
RAM: 8GB DDR3 1600Mhz
Motherboard: ASUS A88XM-A Matx
Processor: AMD Athlon ii x4 740

I recently tried changing the RAM to 16GB (4 Sticks 2GB each) 1333Mhz and the PC ran fine, however I needed to change it back to use the RAM in another build. I changed it back to the original RAM and nothing happened, this failing I reinserted the 16GB of RAM and nothing happened then either.

What I mean by nothing happening is: Fans boot for 1/2 of a second then go no futher, MOBO light is on. I then hit the power button again, and not even the fans boot, until I turn the power switch off and leave it for a few seconds.

I replaced the motherboard and it boot for the first time, but didn't even get to the BIOS just a blank screen, I also changed the PSU and the same problem occurred, however the PSU was a 4 year old one from my friends PC.

After powering it off and on for about an hour it decided to boot, and even turned on after me switching it off, so the problem was fixed!

However me being me I thought I could get the money back by returning the new motherboard as it may not have been a Motherboard issue, but now neither of the motherboards work in this equation, however the newer motherboard has the best luck as at least the fans boot for half a second.

Any help would be MARVELLOUS!!! Thanks
 
Solution
Yes, the motherboard mounting studs/standoffs are necessary: without them, the motherboard won't line up properly with the rear IO shield and slots. Additionally, if you mount the motherboard flat against the motherboard tray, there may be direct shorts between through-hole motherboard components or bottom-mounted SMD components and the tray.

InvalidError

Titan
Moderator
Sounds like something is shorted out somewhere: some PSUs lock themselves out (refuse to try turning on again) until they are power-cycled after an over-power/current condition.

Make sure you have no wires touching metal and triple-check that there are no misplaced extraneous motherboard mounting studs behind the motherboard.
 

faabiian3

Honorable
Oct 12, 2013
25
0
10,530

Hello thanks a lot for your reply. I'll have a look and try to run the PSU directly from the mains for an hour or so.

I have heard that 'standoffs' are required, do these actually NEED to be installed?

- Also I did test one of the PSU's and it seemed to be running fine from the mains.. and the other one seems to run a cycle, starts, off, starts, off.
 

InvalidError

Titan
Moderator
Yes, the motherboard mounting studs/standoffs are necessary: without them, the motherboard won't line up properly with the rear IO shield and slots. Additionally, if you mount the motherboard flat against the motherboard tray, there may be direct shorts between through-hole motherboard components or bottom-mounted SMD components and the tray.
 
Solution

faabiian3

Honorable
Oct 12, 2013
25
0
10,530

You sir are a beauty. I inserted the standoffs and removed the PSU and let it run for a while, replaced the motherboard and nothing happened, I then put the NEW motherboard in and PRESTO! It looks like I fried the previous one, or something in the process, not quite sure what the exact solution was, but it is now working!