Computers basically make two kinds of noises that cause concern: clattering sounds and clicks.
Since the power supply can shock even with the power off, power supplies should not be opened. Also, power supplies are one of the two things that often wear out (the other is the hard drive). So, if one thing goes on a power supply, then the entire unit should be replaced.
- The computer makes a clattering sound when started up in a cold room, but the sound disappears after a few minutes.
This generally is caused by the fan motor in a cheap power supply. The racket is a nuisance, but as long as the fan works and the noise does go away, no action is required. To find out if the fan still functions, put your hand in back of the computer. If you feel a breeze, then the fan is doing its job. If there is no airflow, then the power supply must be replaced. In any event, it's a good idea to let the room first warm up to something over 60 degrees before turning on the computer.
- The computer makes a clattering sound and the sound persists.
- One of the fan motors (either in the power supply, the case, or the CPU) is malfunctioning.
The fan needs to be immediately replaced. If it's the power supply fan, then install a new power supply.
- The CPU fan is hitting a cable or a wire.
The obstruction must be removed immediately. The fan will stop working and/or whatever it's hitting will be destroyed. If the CPU fan stops working, then the processor will overheat and fry.
Clicks generally come from the hard drive. Some hard drives just are noisy. If the hard drive always clicked and the computer seems to be running OK, then just keep making backups as usual. If instead the hard drive suddenly starts clicking and the computer hangs, then all data needs to be immediately backed up and the drive replaced.