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PSU fan spin when system doesn't POST?

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Last response: in Components
December 28, 2006 2:15:56 PM

Should a PSU fan spin up even if the system doesn't POST?

I have a Golden Field PSU (GFT-350) that is supplying power to the mobo (the CPU fan spins up) but the PSU fan doesn't spin.

I'm thinking of replacing the PSU with this to hopefully get the system working again.

More about : psu fan spin system post

December 28, 2006 3:10:27 PM

I'm not totally sure on the specs since the system was just given to me as is. The system worked before I got it, though I haven't been able to get it to even POST yet.

CPU: Intel P4 2.4Ghz
Motherboard: MSI 845GVM-L or 845GEM-L
Mem: 1x512MB DDR SDRAM and 1x256MB DDR SDRAM (PC2700)
PSU: Golden Field GFT-350 350W

When I got it, it was dusty as all get out. I cleaned it up with some canned air.

When I had the HDD, CD, floppy all plugged into power, they powered up, along with the CPU fan. Since it wouldn't POST, I disconnected everything except the PSU, mobo, and RAM. I also reset the BIOS using the clear CMOS jumper. Connected a monitor to the onboard video, but no POST, no beeps.

I noticed the PSU fan wasn't spinning, so I figured this was related to the problem.
December 28, 2006 3:16:05 PM

Some PSU fans are thermally controlled.
If the computer had been sitting around for a long time, the battery may be weak and need replacing. That alone could make it post again.
Related resources
a b ) Power supply
December 28, 2006 4:01:06 PM

I believe one part of the PSU could have died resulting in the computer not posting and the PSU fan stop working. I've had that happen before. I'd replace the PSU in any case just because it's a pile o crap :p  Procede from there.
December 28, 2006 4:39:29 PM

If that doesn't work try alternating memory with only one stick in at a time.
If you still don't get a post take the motherboard out and remove everything except the processor and see if you get a beep. Then try adding memory, looking for beeps and then video card, looking for beeps and post. If you can't get a beep from the motherboard, the motherboard is probably bad. Examine the processor in that case also for burnt marks or you could try a different processor in the machine.
December 28, 2006 8:12:06 PM

I'm pretty sure the PSU doesn't have thermally controlled fans, yeah. It's cheap.

Thanks for the ideas, gang. I'll keep working and post back.
April 13, 2007 1:51:10 AM

So I ended up buying a new Enermax Liberty 400W PSU to see if this would fix the problem. No luck.

I took the system to a local shop. The mobo, CPU, and RAM were all fine. The system POSTs now, maybe because the components were reseated, dunno.

Here's the problem: the shop tested the new PSU with an Antec power supply tester. Each of the rails were fine, but the fault light came on, which indicates the PSU did not send a Power Good signal. Yet the system boots. Am I missing something? How worried should I be about this?