A power supply fan keeps the power supply cool. The semiconductor components get hot in a switching power supply, and this fan keeps things cool and helps prevent the power supply from damaging itself from excessive heat.
As an example, when you play games, the video card requires a lot more current. That means the power supply has to work harder. The switching transistors in the power supply have to operate at a higher frequency and pass electricity through them a higher percentage of the time. That in turn causes them to get hot. The fan helps pull this heat away and protects these components.
To keep the power supply cool. If there were no fan the power supply would overheat and fail.
Most have a fan in them and you can hear when it is on.
cooling the power supply circuity
yes, the power supply provides power specifically to the motherboard in turn dispersing power to all components plugged into the motherboard, hope this helped :)
When your computer will not power on. When the cooling fan of the power supply has failed. When the amount of hardware in use in your case exceeds the power capability of your power supply.
Remove and replace the power supply.
Neither, The CPU is the Central Processing Unit, it only processes information and bits of data the computer sends thru it. The motherboard supplies power to the case fan AND the CPU fan, which is supplied power from the PSU (power supply unit)
If another power supply doesn't work, it's likely your motherboard has failed. It could be that you need to buy a new processor. It may be "fried." However, there may be other causes. It could be as simple as reseating drive cables, power connectors, etc. There is not enough information in the original question to determine what the problem is. (Which fan is on, the power supply or CPU fan or one of the case fans?) A Power supply can be strong enough to get the fan going but not enough juice to power up the system! That ia a weak Power supply that can power up a fan but not the system, try another power supply.
Yes
The power supply that you replaced the old one with might have a louder, faster fan inside. Also, your last power supply could have broke down due to it's fan being shot and it wasn't operating at all.
Switch mode power supply (smps) converts 110-230 volts of alternating current to direct current that computer components need. The fan keeps the power supply cool.
The electronics inside of the power supply will overheat and cause the power supply to quit working. There might even be a small fire inside, or the semiconductors may crack or explode. So it is best to repair or replace the power supply when the fan starts to malfunction, since it will be easier to fix. If you must operate it that way, you should take steps to reduce power consumption and make sure the fan is running each time. Some even insert things in there to start the fan if it is stalled, though that has its risks.