GIVE IT MORE POWER 

If you try to switch on your computer and don't get any lights or sounds at all, it's possible you have a power issue. The issue could be internal or external. 

First, plug the computer directly into the wall bypassing any power straps you're using. Ensure the computer is switched on as well as the plug – if this doesn't work you may have an internal problem. 

CHECK YOUR MONITOR 

Sometimes it sounds as though your computer has turned on but there is nothing showing on the monitor, this is a common monitor fault. 

Make sure the monitor is plugged in and switched on, sometimes the monitor is separate from the computer. Also, check your monitor setting for brightness and contrast. 

UNPLUG UNNECESSARY DEVICES 

If you've tried the hints above but you still aren't getting success then try unplugging the USB enabled devices. This could be the mouse, the keyboard, or something else. 

Occasionally your PC won't turn on if there's some damage to a USB port – it may not be the device causing the issue. Troubleshoot your USB devices until you find the issue.

RESET THE HARDWARE 

Sometimes the issue with a computer not turning on is on the inside. There may be a component that has come loose or a wire on the motherboard. 

If you understand computers it's worth opening up the side panel and taking a look. Check everything is secured and clean away any dust. Try switching it on again.