Desktop Computer boots up into a black screen

This morning I turned on my desktop, everything was fun until the computer suddenly restarted itself and then it stayed on a black screen. I manually restarted it by myself and now i cant even hear the 1 beep my computer always make. After being restarted, it still showed a black screen.

The monitor says that it is entering power saver mode. I reseated the graphics card and that didn't help. I plugged the monitor vga cable to the integrated graphics vga and that didn't help either. So, while the computer was running, I kept clicking the eject button for the dvd/cd drive and it wouldnt open. I then thought it must be the power supply. I had a spare power supply so i took out my old one and installed the spare. It was finally working and booting into my windows screen. Then, it restarted again and the same thing happened! BLACK SCREEN. Idk what the problem is. Please help!

EDIT: I waited for about 30 mins. I booted my computer up and i heard the 1 beep sound it made and the disc drive also worked. BUT it still is on a black screen... :/

 

UPDATE: I turned off my computer and tried to boot it back up and it didn't work... I then reseated the memory again and booted it back up and it worked. IS my memory faulty or what?

 

So you can see the POST text and enter the BIOS? If so can you go to the Hardware Monitoring section and have a look at the temps and fan RPMs plz.

 

Yes now I can see the POST.. But I think i know what the problem is now. I took out one of the memory ram and tested if it will work and my computer booted normally. My computer is working normally with the 1 stick of ram instead of the 2 sticks of ram. I suspect there is complications with one of the memory ram.