Overheated something... Not sure what

[ifbatmanwasreal]

OS: Windows 7
Graphics card: Radeon HIS 7870
Motherboard: Asrock h77m
RAM: 8gb
Processor: Intel i5
Power supply: OCX mod stream 600w

So I'm an idiot... I think I overheated something from bit coin mining too much. I was on my computer and I left my room, when I got back my screen was black. Computer still running. But screen totally black. Turning the monitor on and off again made it reappear but only for about five seconds. I changed the PCI-e slots and tries again a day later. It lasted about 15 seconds. What I break? And how do I fix it?

[Calum]

It's unlikely that anything will have overheated from running at full load unless there was already an underlying issue.
When you say it lasted about 15 seconds when you tried again, what exactly happened?
How old is your power supply?  It should in theory power your system with capacity to spare, but it's not a very good unit so it's possible it has gone south.
Have you tried the system without the graphic card, just running off the onboard graphics?

[ifbatmanwasreal]

I got to log in and then my screen went black again. And my power supply I bought when I bought all the parts to this computer about a year ago. And I don't know if I'm doing something wrong but if I take out the graphics card I can't plug in my monitor.

[Calum]

Try booting into safe mode if you can (keep tapping F8 on startup until you get to the advanced boot menu), and uninstall the graphics driver from there, then reboot and see what happens.  It's possible that this is a driver issue.
Your motherboard has VGA, DVI and HDMI outputs for the onchip graphics, what connector does your monitor use?

[ifbatmanwasreal]

I'm not a smart person. Its a VGA cable I just can't get my graphics card out I feel like I'm going to break something when I start pulling on it. And I wasnt able to boot into safe mode.

[Calum]

There's usually a little tab holding the card in its slot - on your motherboard it looks like you'll need to push it down in order to remove the card from the slot.
When you say you couldn't boot into safe mode, did you not get the option, or did you try and it didn't work?  It's just a case of constantly tapping F8 right after the motherboard BIOS screen disappears to get to the boot menu.

[ifbatmanwasreal]

Safe mode and uninstalling the driver did nothing... does that mean its not the card?

[Calum]

So after rebooting into normal mode, you get the black screen again?
That rules out the driver as being the issue, but not necessarily anything else.
Your best bet now is to remove the card and try booting on the onchip graphics, to rule out the card.

[ifbatmanwasreal]

I got the card out and tried again... same thing.. black within ten seconds.

[Calum]

Nowhere, leave them unplugged.

[ifbatmanwasreal]

Yeah I edited that comment I did that anyway and the same thing... still goes black

[Calum]

That's very odd, normally it's an issue with the display driver or device when that happens.  So in safe mode, it's fine, no problems with the display?  But in normal mode, you log in, then a few seconds later it goes black, even without the 7850 installed?

[ifbatmanwasreal]

In safe mode and normally the screen turns black within a few seconds

[ifbatmanwasreal]

So what do I do now?

[Calum]

Enter the BIOS and reset to defaults, if that doesn't work try the system with each stick of RAM individually in case it's a memory issue.  Failing that, I would suggest trying a repair install of Windows.