There can be several reasons why your PC won't turn on, but here are some common solutions:
1.Check the power supply and plug: Make sure your computer's power cord and plug are connected correctly and securely. If the power cord is damaged, replace it with a new one.
2.Check the battery: If your computer is running on battery, check that the battery is fully charged. If the battery is low, charge or replace the battery.
3.Restart your PC: Try pressing the power button to restart your PC. If your PC still won't turn on, try pressing and holding the power button for a few seconds to force your PC to shut down, then start it up again.
4.Check memory: If your PC runs out of memory, it may fail to start. Try reinserting the memory module or replacing it with a new one.
5.Check the hard drive: If the hard drive fails, it may fail to boot. Try using a hard drive detection tool to check if the hard drive is corrupted and try to repair or replace the hard drive.
6.Check hardware connections: Check whether your computer's hardware connections are secure, such as hard drives, memory, graphics cards, power supplies, etc. If the hardware connection is loose, plug it back in or replace it with a new one.
7.Reinstall the system: If none of the above methods solve the problem, you may need to reinstall the system. Back up your important data, and then reinstall the system using a system installation disk or USB flash drive.
If none of the above methods can solve the problem, it is recommended to send the computer to a professional computer repair shop for repair.