Computer Won't Boot When CPU Fan Is Plugged In

**An-225** · July 17th, 2009, 18:31

Exactly what the title says...when I try to boot up my PC, the fan starts making a tremendous amount of noise (sounds like a 747 to be honest), and I get nothing but a black screen. The light on my monitor remains amber, indicating that it is getting no display whatsoever...

However, when I unplug the CPU fan, it boots up normally (save for a message stating that the fan is not plugged in) and I can plug it in after Windows has started.

Any help is appreciated!

Pentium 4, 3.2GHz
2GB RAM
Nvidia 8800GT

harleyman · July 17th, 2009, 18:42

Hmmm

Well it certianally seems that your CPU fan is broken.....

That can cause it to not boot in as the chipset reads the fan speed..

Its odd that later you can plug it back in and all is well...

First thing I would do is get a new fan and hope thats it..if not then it seems that it would be related to the motherboard / PSU at the high amp pull at boot...

But I opt that its just a bad fan and needs replaces.....

Do you have one,(ANY) fan that you can just plug into that CPU spot on the motherboard and test?

**An-225** · July 17th, 2009, 18:56

I have no spare fans, but I'll try and get this one replaced. This PC is getting quite old now, having been ordered at the end of 2004. Everything but the GPU and RAM is stock Dell.

harleyman · July 17th, 2009, 19:03

Good luck...Let us know how it all goes..

Sorry I can't point you in the right direction for a fan...But we shop on different continuents...LOL

**txnetcop** · July 17th, 2009, 19:18

You may have a bad power supply. If you have a spare that is equivalent to what you have now put that one in. If you don't have one buy one you can always take it back if you keep the box, but my bet is your power supply is failing
Ted

***kilo delta*** · July 18th, 2009, 11:50

Originally Posted by txnetcop

but my bet is your power supply is failing
Ted

Yep, I concur. You'll pick up a decent aftermarket psu for cheap.

**txnetcop** · July 18th, 2009, 14:42

Originally Posted by An-225

Exactly what the title says...when I try to boot up my PC, the fan starts making a tremendous amount of noise (sounds like a 747 to be honest), and I get nothing but a black screen. The light on my monitor remains amber, indicating that it is getting no display whatsoever...

However, when I unplug the CPU fan, it boots up normally (save for a message stating that the fan is not plugged in) and I can plug it in after Windows has started.

Any help is appreciated!

Pentium 4, 3.2GHz
2GB RAM
Nvidia 8800GT

perhaps I should explain my answer to check your PSU. While you may need a fan...consider this. If a dragging fan can stop your computer from booting it is because it cannot supply enough power to run a dragging fan and boot the system. Your Bios should contain a CPU fan failure alert. You might check your bios to see that it is on as well. Most Dells had or have this in their BIOS even the older ones. But a noisy fan itself would not cause your computer to not boot. It probably is a power on issue from the PSU failing.
Ted