your last chance before thinking that it maybe be an HW problem, could be to do a secure erase, with a back up of everything first, if even this don't work , then is guaranteed that you have a HW problem
this is the fastest way to resolve this thing, don't waste too much time searching to find the actual problem
Is there any way to check the motherboard on desktops to see if thats the issue? I know on certain laptops you can do somethings on startup even if the computer won't load to see if its the motherboard. Like a certain light will blink 3 times or not blink at all.