PSU Fan always running

[nweaver]

Working on my mom's PC....Emachines, Celeron 2.6, blah blah blah

Dead PSU, so I swap in an Antec 300W to test with. (Old PSU wouldn't spin up the fan, with the right pins jumpered). Once I hook the Motherboard connection up (both ATX and the other yellow and black one) and plug the PSU in, flip the switch. To my suprise the PSU fan starts spinning. I thought the computer was booting up, until I realized the CPU fan wasn't spinning. Hit the button on front, it starts booting up. Windows appears to be dead (sudden reboot as soon as you hit the desktop) so I booted an Xubuntu live CD to make sure it would stay up (it does).

Any ideas? I'm thinking she might have burned the PSU out because the fan was on 24x7 until it failed, and the old unit overheated.

 

[SparkyJJO]

I've seen something similar with an emachines I worked on. The PSU - a crappy featherweight Bestec - got damaged from a power surge, and the damaged PSU then damaged the mobo, which in turn when I replaced the PSU caused that PSU to kick on as soon as power was given. Wasn't quite the same as you though, it would turn on-off-on-off-on-off-on-off-on really rapidly which obviously couldn't have been good on the HD or anything else.

In the end, they got a new system. The board was all screwed up and it made more sense to ditch the whole thing and replace it.

 

[nweaver]

hmmm...it was just running Xubuntu for a while, so I think the rest of the HW is fine, it's probably something going on the Mobo though. I did check, and caps look fine. For now, she will just put it on a powerstrip and turn the power off when not in use.