CPU fan spped is too high and too loud
 

Hi. Please help.

I got a new ETS-T40 Black Twister CPU cooler a few days ago. The installation was easy. I plugged the cpu cooler cable to 4pin cpu fan. The fan was running at 750-800 RPM which is perfect for me because it's not noisy. The problem was the blue LED light on the fan didn't come on. The only way to get the led light to work was to plug the cable to 3pin sys fan, but the fan was running in full speed 1800 rpm and it's really loud. How can I fix this problem?

Motherboard: Gigabyte MA77OT-UD3P
Processor: AMD Phenom(tm) IIx2 550
Memory: 4GB RAM
GPU: NVIDIA GeForce GT610
OS: Ubuntu/Kubuntu

The 4-pin connector uses a special signal on the 4th pin to bring down the fan speed. If you plug it in a 3-pin connector there is not such a moderating signal. So your fan runs at full speed. As it seems the manufacturer has connected the blue LED to the moderated signal instead to the +12V.

If you have sufficient technical knowledge you might want to try to reconnect the LED wire to the unmodulated 12V. If you don't know what I am talking about or need more instructions, you'd better leave this alone.

jlinkels

Hi jlinkels. Thanks for the respond. You are right, I don't know what you are talking about, but on the product box it's showing Fan Rated Voltage 12V. Is this what you are talking about?

Thanks,
Keani

Fan rated 12V means that the complete device is designed to be connected to 12V. You connected it correctly. The problem is that both the fan and the LED are connected to the same speed-controlled voltage. For the fan that is fine, it runs slower. As it seems the LED doesn't work at this modulated voltage. Internally in the device, the LED should have been connected to the unmodulated 12V.

jlinkels

Thank you jlinkels. I better leave it alone. The computer might be loud but it sure looks pretty. You have solved my problem. Thanks again.