New CPU Fan Won't Work!

LilMomma

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Jul 17, 2009
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Hi, I have a Dell Dimension 2300 desktop. The original CPU fan for my PC started making a bunch of high pitched noise and it eventually just quit working. Which ok, this PC is a 2001-02 model, so I figured maybe it was time for a new one anyway. So I went to my local computer parts store with my old CPU fan and they sold me a new fan that was like the old fan. Well this new fan isn't working in my PC. And when I got home with it I discovered that it was a tad bit different than my old fan. The older fan just had one wire coming from the fan and it was a small 3-pin connection that connected directly to the motherboard. This new fan has 2 different wires. One is a white wire that has the 3-pin connection that connects into the motherboard (where the older fan connected). And then it also has a red & black wires that lead to a 4-pin connector, but the only place available to put this 4-pin connection is to plug it into the hard disk drive/area with all the wire coming from the power supply. There is no 4-pin connection on the motherboard. I'm not sure if I need to plug in BOTH of these to get the CPU fan to work properly or not. However, if I just plug in the white wire with 3-pin connector into the motherboard, and boot up my PC I still get the "CPU fan not detected" message and the CPU fan doesn't work. It's not turning at all. If I plug just the 4-pin connection into the HDD/power supply (there are 2 available area to connect) the PC won't even boot up. It just won't turn on. So what gives? This seems like a no win situation.

Can anybody offer any help or advice? Thanks in advance.
 

Conumdrum

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Nov 20, 2007
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You'll have to wire it in somehow to the output of the PSU. And in the bios there should be an option to disable the fan sensor, so it doesn't do that.

Oldd Dells used a messed up wiring for fans and such, they don't any more.

Just plug in the fat one (called a 4 pin molex BTW) to the PSU connector, it's just like a HD power plug and don't plug the 3 pin one in anywhere.
 
The red and black wires are for power to the fan. That one has to be plugged in. The other one is the sensor wire. It should be plugged into the mobo fan header; it won't draw power from there, but will report fan RPMs.