CPU fan not working? Ideas?

most likely its a bad fan......connect the fan to a 12V battery and see if it spins.
or, u could get a voltmeter and check if there is a 12V voltage across the connecting pins on ur mobo where u plug in ur fan

btw.....i would recommend not to turn on ur pc till u fix the issue

Thanks for the quick reply. It's pretty dissapointing if it turns out to be a bad fan. Or worse, the mobo! I just bought the parts yesterday.

sarwar_r87: Unfortunately, I've already tried to boot the system. When I noticed the fan wasn't spinning, I turned off the power.

IH8U: yes, it's connected to the correct header. I was pretty paranoid about that so I checked and rechecked. I think I may have to run out and buy a new fan today since I wanted a better one in case I tried to OC at a later date anyways.

I took the fan into the shop where I bought it and the tech tested it. It works. Now I've taken everything apart and put it all back again to make sure I didn't miss anything and it still won't come on. The system boots up but shuts off after a few seconds. I think I might take the whole thing into the shop tomorrow to have them look at it because this is beyond my abilities I think.

If you don't like the hassle, just get an aftermarket fan/heatsink that has both motherboard power connector and 4 pin molex power connector. This way, you can connect it to the psu's molex connector, and get power directly, instead of going through the motherboard. Even if the mobo isn't sending power, it doesn't matter.

The Zerotherm Nirvana that IH8U linked earlier is like this. It even has a fan speed controller so you can change speed when connected through molex.

Yeah, I was looking for an aftermarket fan but they are all so HUGE! Even the guy in the tech shop was iffy on whether some of them would fit or not because the motherboard has some built in piping and a huge heatsink for the pipes. And I can't return a fan once it's been opened so I can't really get one until I'm 100% that it will fit.

kyeana: The system will only power on for a few seconds and then turn off so I can't even get into the bios. I'm going over to my brother's place this morning to see if he can offer any suggestions as well, maybe I keep missing something...

However, I think the issue might be the motherboard not providing power to the connector. If we can't resolve the issue, the shop will have to replace this mobo for me of course.

Thank you all for you suggestions, I'll let you know how it goes.