PSU Problem

Dazzlercee · 11 Dec 2006 at 10:03

Hope you can help!

My brother has just installed a Leadtek 7900GS and the system will not start at all. To me it seems like a PSU problem. All fans spin for a couple of seconds and then nothing....

I have had a quick look for him and have found that if I disconnect the 4-pin ATX power cable from the motherboard then everything powers up, i.e. fans, DVD, HD etc. However the system will not post (as expected). As soon as I plug the 4-pin connector back into the mboard, everything is dead once again. To me this behaviour indicates that part of the PSU has either tripped or blown, most probably blown as it does not reset.

The PSU is an Akasa 400W with one 12V rail at 13A and the other at 15A. I think the 7900GS requires 20A combined.

Any help appreciated although I think a new PSU is in order.

mattbill · 11 Dec 2006 at 10:11

are you able to try a different psu before buying a new one? just to confirm it is that.

Dazzlercee · 11 Dec 2006 at 10:39

Unfortunately we do not have a second suitable PSU to test with.

Thanks.

Sean_UK · 11 Dec 2006 at 13:24

I know of a few people who installed the 7800+ bliss AGP (not same card granted, but very simular power demands) and some got problems with 350W to 400W PSU's. Iirc they purchased 430W PSU's or higher and no more problems. Just to be sure, the line feeding GFX card extra power is not feeding any other stuff is it, i much prefer straight from PSU with no branch offs route.

Snapshot · 11 Dec 2006 at 15:33

Can you put a lower power graphics card in to see if the PSU will work with that?