Today i bought a new chassis cooling fan, i installed it to the case and the 3pin connector on the motherboard, after doing that the fan was running very very fast and it's making a "Bzzzzzzzz" noise, i took a look and i found out that the power supply fan was running very slow and it stops from time to time while the case fan is running very fast and making that noise, but now it's running just fine... it's not making any noise or anything, but everytime it makes the noise again...
What should i do ?
Is that normal ? Is it damaged ? Should i return it to the store ?
Depending on what type of PSU you have, it is common for better ones to have variable speed fans that accelerate and decelerate on the heat/load on the unit.
When the case fan is plugged into the motherboard -- you can control the speed of the fan from your PC. By default it is probably set to 100%. You should be able to turn it down. Depending on what kind of motherboard you have, you can either control that from the bios, or use software on the PC to control fan speed.
Is it possible the fan is rubbing on something that makes it buzz? Otherwise its probably just the speed its going at (too fast).
Can you post your motherboard, PSU, and OS info? This will give us a better idea of how to proceed.
Would help to know the fan and psu in question. Your psu might turn it's own fan off if its at a low enough load. And as deadlock said, the case fan your talking about is probably running at fullspeed which is probably what is causing the noise.
Of course, but whats the point of putting that on a mobo that didnt support a variable speed fan? Its evidence that he can change the speed.
Not necessarily. Just because it has a tachometer to read the RPM doesn't mean the fan will be controllable. 3 pin fans can be controlled by voltage regulation, as can 2 pin fans (which don't have a tachometer).