Did I kill my PC?

[mister yuk]

Is my PC dieing? I posted to another online forum earlier but I thought I'd try here as well. Below is my original issue.

I built my PC four years ago. I left my PC on overnight on the title screen of a game. I woke up this morning and the monitor was off and when it turned it on it did not detect an input. I tried a different hdmi cord and still nothing. I plugged the hdmi into the on board graphics and now I have a picture. My device manager cannot detect my graphics card. I reseated the graphics card and still does not work. I checked bios and the video default is set to my pci slot 1. Still does not show up in device manager. I followed some process to show hidden items in device manager and now I can see my GPU in the list but the properties say it is not connected, I then let Windows update the driver but that didn't solve anything.

I'm going to take a break because I'm hungover and frustrated my Saturday started like this. . When I come back I'm going to try to seat my GPU in my pci slot 2 and see if maybe pci slot 1 died. If that doesn't work I might try and put the GPU in my buddy's machine later and see if his pc can detect it. Does anybody have any other advice or thoughts on what else I can do to remedy the GPU?

The card is Nvidia GTX 780ti

Thanks so much for reading and in advance for your thoughts!

EDIT: So I took a nap, came back and my PC was still turned on, moped around for a couple of minutes, smoked a cigarette, came back and my PC was off. This is very strange, so I went to turn it back on and nothing. It doesn't seem to have any power at all. I checked all connections and nothing. What is going on?!? It was functioning as normal before with exception to the GPU. There is a light on the mobo that is showing me there is some power going to it but still will not turn on. :"(

EDIT2: I waited a bit and tried to turn on my PC again and in a split second lights came on and then instantly turned off like it was booting up but couldn't complete. I unplugged the PC and then plugged it back in and the same thing happened. Once more I unplugged it and plugged it back in and it fired up! The GPU is also working now!!!!! What the hell!!!! Is my PC haunted??

 

[Tradesman1]

Do you have another PSU you could try, yours may be dying a slow death

 

[Karadjgne]

2 possible causes I can think of.
1. Psu is dieing a slow death, as Tradesman1 so kindly pointed out.
2. You have an issue with an old and tired wall outlet that is now weak. This will case the internal claws to separate when heated by long term loads like leaving a pc on for extended periods. Once the claws cool, by no pc on, they shrink, causing contact with the plug prongs, and pc gets power again.

Check the wall outlet. The plug should be a little stiff to insert, if it's really loose feeling, it needs replacing.
Try your pc via extension cord to another outlet, preferably bathroom or kitchen. See if issues remain.