White non-blinking line in top-left corner showing when trying to start pc

[Justas]

Hello, when I start my computer it shows a white line that isn't blinking in the top left corner. It stays there forever and the computer doesn't start. However if I turn the computer off by the button that stops electricity going to my pc it starts up. I read that turning your pc off like that is bad for it so i'm trying to find a solution (if I turn it off normally by clicking shut down, the next time I turn it on  I get the line again). If anybody can help, you have my thanks. This is my first time posting here and i'm not an english speaker so sorry for grammar mistakes.

[DaveLembke]

Your system is almost acting as if its going into a sleep mode vs shutdown. Check power management and make sure that shutdown actually shuts down your system. I had a computer in the past that it had some RAM sticks in it that ran fine when the system was running, but in sleep mode where the RAM stores data for it to go live again and boot faster the system would act like yours and I would have a black screen and fans going. By unplugging the computer or flipping the power switch and starting fresh boot it would boot up fine. My solution was to replace the RAM.... BUT before you do that check into your shutdown to make sure its meant to shutdown vs sleep or hibernate and lastly before a RAM replacement I would suggest backing up your data to an external drive or cloud storage and then perform a clean install of the OS just to be sure its not some other issue. But this sure sounds like the RAM issue I had with a system that was going into sleep mode and didnt come back out of it healthy and only way to get it to boot was to replace the Value RAM in it with good name brand RAM in which the problem was resolved. Also MEMTEST86 didnt detect any flaws in the RAM, but there was with sleep state with this value RAM.