CPU fan stuck on full speed....help please

[eric1123]

ok, it started of with me being bored and wanted to make something...so i decided to get an old cpu fan and put led lights on it. It was all fine and i double check it all for touching wires and stuff like that. When i hooked it up in my computer it worked, but when i went to tuck all the wires away, i heard a small "pop" and then the fan started spinning at full speed. i didnt do anything unusual to the fan except that the wires for the plug broke, so i figured no big deal, ill just solder them back together and wrap it with electrical tape.

I tried the other cpu fan hoping that it would work but that one spun up at full speed too......i tried changing the speed in the program speedfan but it didnt work, so now im stuck with a really loud fan. Could the problem be that possibly one of the plug wires touched and shorted something on the motherboard or would it be something else? i reallly dont want to have to buy a new motherboard......Any help would be great. Thanks

[Gabriel Torres]

Hi,

It seems that the short-circuit burned something on your motherboard...

Cheers,
Gabriel.

[eric1123]

yea thats what i thought.....would there be any way to fix it besides buying a new motherboard? i do have good knowledge of electronics and soldering and stuff like that, except for the fact that i let something short-circuit lol but you know....

[reidy-]

If you can find the component that's blown and locate where the short is then yeh, you can rectify the short purchase a new part attempt to solder that new piece in and then test the moatherboard and potentially destroy you'r entire PC

If I were you I would either put up with it or buy a new moatherboard, its hardly worth the risk

[Gabriel Torres]

Hi,

Yes, there is a workaround.

If you pay attention the fan connector has 3 or 4 pins, so the fan has three or four wires. There will always be a black wire (ground), which is connected to pin 1. The wire connected to pin 2, which color can vary, is the +12 V feed for the fan. The other wire(s) are rotation sensors. What you can do:

Remove the ground (black) wire from the fan connector and connect it to any +5 V source inside your PC. For example, to any red wire at a spare peripheral power connector. Keep the other wires on the fan connector.

With this change, the fan will be fed with +7 V (12 - 5 = 7) instead of +12 V, rotating at a lower speed.

I hope this trick works for you.

Cheers,
Gabriel.