Ever since i upgraded my cpu, fans started to spin a lot faster while the temperatures are normal. I changed the fan speed in bios but it doesnt work. Is it a bad cpu or did i somehow damaged the mb?
cpu: i5 6500
mb: msi b250 pc mate
In the process of upgrading the CPU, did you do a BIOS Reset on the mobo? Usually that involves removing a small disk battery and / or moving a jumper on pins (see your manual p. 36). I ask because you might have reset the CPU_FAN1 configuration.
Another possibility occurs to me. If you plugged the CPU cooler fan into the PUMP_FAN1 header instead of the CPU_FAN1 header, the PUMP header does no control, and always runs its device at full speed.