Has also been caused by failing HDDs. Here's what to check.
Go get SPECCY (it's free) and run it. Look at the drives and look at SMART values 01 and 07. If they are out in the thousands you found what I'm finding.
-> But you are writing it's all black and no longing booting. That points to some other failure like motherboard etc. It doesn't tell you which though. Make the PC as small as possible. What's left are the suspect parts.
Okay so i was playing games then
A blue screen with "video_scheduler_internal_error" popped up
After the pc restarted
It was just black.
It seems like my monitor notices my pc turning on but still black.
-------
Things ive already tried and nothing happened:
--------
I have tried using the internal graphics in most of situations with still no luck.
I reseatted the gpu. Even tried the other pcie slot.
I removed all unnecesarry stuff like keyboard and etc.
I tried hdmi port, dvi port (my main is displayport)
Did it all again with a 2nd monitor.
Took out ram, unplugged sdd and hdd
Cmos battery reset
-----------
Im just lost already.
only things i havent tried are removing the cpu and putting it back. (Since its hassle)
And I dont have a 2nd psu for test.
I did all that and the monitor still black with nothing else

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic