PC stuck in rapid reboot, PSU failing?

[qkslvr221]

Hello all,

I have a 5 year old Sony desktop and while I was browsing the web, it randomly shut into a rapid reboot mode. The only way to stop it was unplugging the PSU cord, and now whenever I turn the PC on, it does this exact same thing. The front LED repeatedly dims, the cpu fan halfway spins up, as do the optical drives. I have unplugged every other component from my power supply other than the motherboard, and it still does it.

Do you folks think my PSU is failing? It hasn't been whining or making any strange heat/noises, and the fan is working well.

 

[eplebnista]

When that happened to a relative's PC, it turned out to be bad capacitors on the motherboard.

 

[qkslvr221]

Hmm, is there any way of testing for that? I would like to try the PSU in another computer but all the other machines I own are the 24 pin configuration.

 

[mpilchfamily]

There could be a number of problems. PSU, Motherboard caps, and RAM. Check all the caps on the motherboard and make sure none are leaking or buldging out on the bottom and top. If all is well there then you may want ot get your hands on a PSU. Borrow one if you can and see if its the PSU. However unlikly the RAM is as a problem if all elese fails then it may be the RAM. But if you can't get the system to boot then you won't be able to run Memtest to check the RAM.

 

[qkslvr221]

RAM is fine, this is either a PSU or motherboard specific issue. Is there a way to safely test the output of this PSU with a multimeter?

 

[GalvanizedYankee]

Originally posted by: eplebnista
When that happened to a relative's PC, it turned out to be bad capacitors on the motherboard.

I bet you didn't even clean 'n inspect the mainboard.

 

[eplebnista]

Originally posted by: GalvanizedYankee

Originally posted by: eplebnista
When that happened to a relative's PC, it turned out to be bad capacitors on the motherboard.

I bet you didn't even clean 'n inspect the mainboard.

I actually pulled it, replaced the bad capacitors(which fixed it) with UCC's from mouser, and sold it on eBay.

The board I bought to replace it had rubycon's in the CPU/VRM area and is still working fine so far after a year and a half.

 

[GalvanizedYankee]

Excuse me eplebnista, I was talking to the OP.

A cycle of reBOOTs is most often Badcaps. I have done several sucessful recaps myself.

 

[eplebnista]

Originally posted by: GalvanizedYankee
Excuse me eplebnista, I was talking to the OP.

A cycle of reBOOTs is most often Badcaps. I have done several sucessful recaps myself.

No problem. :beer: I've misquoted a time or two myself .

 

[qkslvr221]

I've inspected all the caps, no bulging or leaking whatsoever. I did manage to test a good power supply on the board, but it had the same issue. It's the motherboard for sure now, thanks for all the help!

 

[GalvanizedYankee]

Originally posted by: qkslvr221
I've inspected all the caps, no bulging or leaking whatsoever. I did manage to test a good power supply on the board, but it had the same issue. It's the motherboard for sure now, thanks for all the help!

Caps can be bad w/o any external signs. This is why the techs at Badcaps dislike boards or cards that are populated with Teapo capacitors. Teapo work OK in PSUs but can fail w/o visable signs on boards. I am not sure why.

EDIT: Instead of swelling or venting a cap can push its bottom bung out, this will cause the cap to tilt slightly.