If your computer has no lights, no fans, or a black screen (power-on self-test failure): Start with a hard reset.
Unplug USB drives, printers, external hard drives, and cameras. A faulty USB device can prevent booting.
If you ask for help in a forum, always give your PC specs (CPU, RAM, GPU) and describe the exact symptoms! If you are still having trouble, let me know: computer trouble shooting
If you recently added new RAM or a new graphics card, remove it to see if that solves the issue.
If your fan is running loud or the computer shuts down randomly: If your computer has no lights, no fans,
Make sure air vents are not blocked by dust or blankets.
Ensure all power cables are securely connected to the PC and the wall outlet. If you ask for help in a forum,
If your computer is acting up, don't panic! Most issues can be resolved with some simple troubleshooting. Phase 1: The "No POST" / Won't Turn On Panic