i have a red LED coolermaster fan with a 4 pin connector and i plugged it into the 4 pin connector on the motherboard and the leds were on but very dim and the fan wouldnt spin, so then i plugged it into the 3 pin connector on the motherboard and the fan was working fine but i want to be able to have it in the 4 pin connector so i can cchange the speed because its a very fast fan
I have a fan with the 4-pin connector and I plugged it into the 4-pin connector on my motherboard, and the LED was working, but was very dim, and the fan wouldn't spin, so then I plugged it into the 3-pin connector on my motherboard, and the fan was working fine.
Looks like the 4-th pin on your fan's connector is defective. Maybe RMA it?
Some motherbards have a tempature sensor onboard so when he case temp. gets so high it will start the PWM fan, the higher the temp. the faster the fan will spin . Read motherboard manual and it should tell you if you have that functionor not.