PSU Dead but not Dead, Internal Capacitor?

grimmysnr

Distinguished
Jul 18, 2006
74
0
18,630
I just though I would ask to see if anybody has ever heard or seen this happen before. I am pretty tech savvy and repaired my fair share of PC's but over the last couple weeks my PC has been acting quite strange. Sometimes it would just turn itself off with no apparent warning or command. Then once it would turn off if it sat for more than 10 seconds before reboot then the system was completely dead. I would have to play with the main power connector to finally get it to turn on. One day I went in and nothing no matter what I did it just would not turn on.

I replaced the motherboard and I still got nothing but the standby power light. I have a power supply tested and hooked up all connections including the 2 12v connectors. The PSU fired right up and all freqs and volts read perfect. If I reconnected the power supply to the computer within a few seconds of starting it with the tester everything would fire up and the OS install would go through the motions. If I shut down the PC, however, then it was dead agan. I had to use the tester to 'jump start' the PSU and then plug it back up to the mobo.

Its a OCZ GameXStream 700w PSU i have had since 2007. I for the life of my cant figure out why or how this thing is doing this. I have had bad PSU's before but it was always a rail failed or low voltages or the thing just died. I have never jump started a freakin PSU before.

I am thinking maybe a capacitor or something? Its a good PSU but I dont know if its repairable or not. I already replaced it and my system is up and running again. I would just hate to throw away a nice PSU like this.

What do you guys think?
 

shovenose

Distinguished
be careful, the internal capacitors carry a heck a lot of voltage, even when its not plugged in to anything. but i think you whould, IF THE WARRANTY IS OVER, (youll void it otherwise) open it up and have a lookm esp. for brown stuff on top of the capacitors and bulging tops of the capacitors
 
Unfortunately, many of the caps in good PSU's are specifically selected for low ESR values (google it). And your local, friendly electronics store is unlikely to stock them.

A place like Mouser Electronics (TX) will stock them. Nice thing about Mouser is that they do not have any minimum order.