Anyway to test a power supply?

[austin316]

Ok, my computer has been running fine and all of sudden, it would not turn on this morning. I'm switched outlets and everything and some of the lights on the front turn on (card reader lights) but no fans start going and nothing boots up. Is this just a dead PS or likely something else?

 

[GalvanizedYankee]

Odds are it's the PSU. Do you have a spare PSU to install temporarily to see if the comp boots? You need not install it in the case for testing.
Have you ever notice a fart or rotten egg smell coming from the comp over the last year? If yes, the PSU has bad caps. Can you view the caps through the PSU's grill work? Look for bulging or venting.
Is this an older Antec PSU? If so, you can almost bet its bad. Look at the mainboard's caps for signs of failure..if the PSU is found to be bad. http://www.badcaps.net/ident/

Capacitors normally fail as an open circuit. Failing caps generally die when they cool off but if warmed with a hair dryer will function again if only briefly.

 

[austin316]

I went ahead and bought a new power supply, but no luck. The PC still won't boot up. I'm guessing its got to be the CPU or the Motherboard. Anyway to determine which one is the problem? I hate to buy a new mobo and find out that is not the problem.

 

[GalvanizedYankee]

The newer PSUs need a slight load to turn on, the older types do not need a load to power up. On the 20/24 pin plug will be a green wire...jump it to any black(ground) and the unit should turn on. Test the old unit and maybe take back the new one for refund.

Check out the flow chart at mid-page for failure to boot.
http://www.fonerbooks.com/pcrepair.htm

 

[John]

Originally posted by: austin316
I went ahead and bought a new power supply, but no luck. The PC still won't boot up. I'm guessing its got to be the CPU or the Motherboard. Anyway to determine which one is the problem? I hate to buy a new mobo and find out that is not the problem.

Disconnect everything from the mainboard (mb) except the cpu. Now pull the mb out of the case and set it on a box, reconnect the ATX psu connection(s) to the mb only, use a screwdriver to short the 2 pins for the case power switch on the mb to power it up. If it still won't power on it's probably a bad mb if you take statistics into consideration. A local shop should be able to test them for you.