These solutions are mostly from experience so they are not fully reliable…
I suggest reading this whole article before starting anything.
'''Complete Guide/Solution:'''
# Check if the monitor power cable is plugged in and or video cable (eg. HDMI). Quite funny although has happened.
# Check video cable is broken by testing with another cable or looking for visible defects.
# Check if you have a '''broken monitor''' by checking the monitor status light and trying with a different monitor.
# '''If these steps didn’t work than sadly it’s time to start looking inside our PC… Make sure to unplug the PC anytime your touching anything inside the PC. Try avoiding touching any tiny parts on the components as well.'''
# Check if the PC’s RAM and GPU are fully inserted into their slots and in the rights slots. Some motherboards require RAM sticks to be in certain slots first before others.
# Clean any dust out of the PC as this may cause shorts and also stop the PC from cooling properly.
# '''If none of the steps up to here has worked than their might be a broken part:'''
## '''Broken RAM:''' Check if the PC works with each individual RAM stick in the first, second, third and fourth RAM slots. The PC will split its data evenly between each stick; this means if any single one of the RAM sticks are broken than the PC will not function.
## '''Broken GPU:''' If your CPU has onboard graphics than it will be easy figuring out if your GPU is broken. Just plug the monitor/video cable into your motherboard and see if you get an output. If so then your GPU is the problem. Otherwise, try to test another working GPU in your PC.
## '''Insufficient PCU:''' If you have bought a PCU with bad reviews or a PCU that cant handle the amount of wattage your parts need than this could be a problem. Some knock-off PCU’s actually can only supply down to half as what the specified to be able to do.
## '''Broken PSU:''' This one will be pretty obvious. If none of the components (including fans, LEDs) is turning on then its probably a signal of a broken PCU.
## '''Broken CPU:''' This one sucks to check although check if the CPU cooler is properly installed by removing it and checking if the CPU coolers thermal paste has spread on the CPU well. If so then also check if the CPU is cracked by removing it, holding by the sides, and also check if any pins are damaged on the CPU.
## '''Broken Motherboard:''' This one is quite hard to discover although if everything seems to be not running except the PCU fan than this might be true. It is also quite common as motherboards are quite complicated to manufacture. Check to see if there is any visible defects and check all the slots to see if they're damaged.