I have a problem with my PC. These are the symptoms:
- CPU cooler makes 2x louder sounds
- Green light indicating whether the PC is on doesn't show anything. The PC is on.
- Red light (besides green one) is always on.
- Green light on monitor is blinking.
This question is very vague and hard to answer considering the lights you have mentioned are different for every case or motherboard ( what is red light? hdd activity? ), but by the sounds off things, if the cooler is running then its getting power, so i doubt its the power supply. I would nail it down to motherboard, just because you mention the "green light" isnt showing which should still show even if ram or cpu wasnt working.
EDIT: also leave the computer off for a while and see if the cooler still spins fast. if soo then its probably a corrupt bios.
To start, unplug the computer completely, press the power button while it is unplugged. The fans and such may lurch a little at this due to residual power in the capacitors on the mother board and in the power supply, that is what we are eliminating. Restore power and attempt again to start the computer.
If that does not work, repeat this time removing the cmos battery or setting the clear cmos jumper prior to pressing the power button while unplugged.
If you are still having issues, disconnect everything from the motherboard except, video, ram and CPU. Attempt again to start the computer.
If your issues continue try using a different power supply. Cheap power supplies have a life expectancy of about 6 months in a busy system.
If your issues continue remove and reinsert your RAM. Try again.
If your issues continue remove and reinsert your CPU. Try again.
If your issues continue remove and reinsert your Video.
If your issues continue locate a replacement video card. If you have onboard video this is also applicable, get or borrow a card that can be placed in a socket and attempt to boot with it.
If your issues continue replace your RAM, or try only using one half of it and in different sockets.
If your issues continue replace your CPU.
If none of this has worked to restore your system your mother board is likely dirt and you will need to replace it.
If one of the above steps worked you have likely found your problem. If you removed everything to get to this point add one component at a time back to the system until you are fully functional, doing a boot between each addition.