I've been playing D3 with dual monitors since launch day. I'll have the game on my nice samsung monitor and chrome open on my old dell monitor. I'd have the game running in fullscreen windowed mode to easily switch between the 2. I did notice that the D3 frame rate drops to about 1 fps when I click outside of the game to do something in chrome, but the game is still running on the other monitor.

This never seemed to be an issue until last night when I was in chrome loading up a video with D3 running on the other monitor and my PC froze. I powered down the machine and started it back up. Selected "Start Windows Normally" at the boot up menu and it froze again during the start up. I powered it down and attempted to restart it a second time. This time, nothing even appeared on my monitors. My samsung (which uses HDMI) would just flicker between HDMI input and Analog input, but just switching between black screens. The PC sounds like it's running fine, but seems like no signal is going to the monitors.

I called a tech savvy friend who said my video card (a 7870) may be over-heated and to leave the machine off over night. I did so and checked it this morning and got all the way to the Start Up Repair progress screen before it locked up again. I powered it down again and restarted it soon after. Managed to get a little further in the Start Up Repair progress before it crashed again.

Could D3 in the background using dual monitors have caused this? I opened the side of the tower and turned it on to make sure the graphics card fan was working, and it was indeed spinning. Really don't know what happened. Can anyone provide some insight?

UPDATE: After some of your recommendations, I tried plugging my monitor into the motherboard's graphics card and I received the same issues. Seems like it might be something more serious than the graphics card?

What framerate was D3 running at? Did you have the frame limiter or vsync turned on for the game? Or was it trying to push as many frames as it possibly could the whole time?
 
In the past I've heard of menu screens trying to push way too many frames, causing overheating damage. I'll run some tests on my dual monitor setup later. The difference in my situation is that I've got my secondary screen running off a second card.
 
edit: Googling "game menu graphics melt" returned a bunch of Starcraft 2 related results. Seems like Blizzard oversight might have struck again.

@Lukeweizer:

@MrKlorox said:

What framerate was D3 running at? Did you have the frame limiter or vsync turned on for the game? Or was it trying to push as many frames as it possibly could the whole time? In the past I've heard of menu screens trying to push way too many frames, causing overheating damage. I'll run some tests on my dual monitor setup later. The difference in my situation is that I've got my secondary screen running off a second card. edit: Googling "game menu graphics melt" returned a bunch of Starcraft 2 related results. Seems like Blizzard oversight might have struck again.

Whilst running this in the same fashion as OP yesterday, the game was barely pushing my card, I don't think it ran hotter than 50c. So I doubt it's anything to do with running multiple monitors or the game pushing anything too hard. But maybe it was?

And the game dropping frames when tabbed out is normal.

All of the details aside it's either your processor or your video card.

Easy fix is to buy a cheap video card from Best Buy or w/e and try booting with that to see if you can get into Windows at all (or on-board video if your mobo has it).

If that doesn't work it's likely your proc. I wouldn't focus on why it happened, just try to figure which piece it is. Getting hung up on details will drive you crazy :P

@MrKlorox said:

@AlexW00d: If you had vsync on, it wouldn't even try to push anything too hard. It'll get to 60 frames and stop trying any harder. If vsync was off it would use as much of your GPU and CPU as it could until one or the other was running at 100%. And with a stock fan profile that doesn't ramp itself up proportionately to the GPU usage, I could see that causing some damage (hence the need for software such as EVGA Precision and MSI Afterburner). The game has built in sliders to limit the framerates to try and avoid things like this, so that's why I'm unsure.

I think the slider defaulted to 150fps for me. Not sure if that was based on my card or just some number it pulled out its arse, but OP has a better card than I, so if I was fine with that I imagine he would? I dunno. If this was caused by Diablo running then Blizzard must have fucked something up big time :/

I stream video in Chrome on my second monitor and play Diablo on my main monitor without any issues. Alt tabbing out all the time. Must be something to do with your hardware... I don't know. Everything is fine for me. Except my damn internet connection.

@MrKlorox said:

What framerate was D3 running at? Did you have the frame limiter or vsync turned on for the game? Or was it trying to push as many frames as it possibly could the whole time? In the past I've heard of menu screens trying to push way too many frames, causing overheating damage. I'll run some tests on my dual monitor setup later. The difference in my situation is that I've got my secondary screen running off a second card. edit: Googling "game menu graphics melt" returned a bunch of Starcraft 2 related results. Seems like Blizzard oversight might have struck again.

I don't think I had v-sync checked. And the FPS were set to the default (150 foreground and 8 background, if I remember correctly). The one time I check the FPS, it was 60. Should I try connecting my monitors to the internal graphics card and see if that actually works?

I'm new to the PC world, can overheating damage be repaired or am I going to have to buy a whole new graphics card?

UPDATE: I just tried connecting my Samsung to the internal graphics card (HD 3000 or something) via HDMI and I had the same problem (no image would appear on the monitor, flickering back and forth between HDMI and Analog feed). Would that mean that it's NOT the graphics card?

I bet you fucked up your computer when you turned it off when it was starting up. I did that to a laptop once.

@Xeirus said:

All of the details aside it's either your processor or your video card.

Easy fix is to buy a cheap video card from Best Buy or w/e and try booting with that to see if you can get into Windows at all (or on-board video if your mobo has it).

If that doesn't work it's likely your proc. I wouldn't focus on why it happened, just try to figure which piece it is. Getting hung up on details will drive you crazy :P

That's definitely what I'm trying to do. I just want it fixed so I can play all weekend. I'm new to the whole PC scene so this is pretty frustrating.

@Dagbiker said:

I bet you fucked up your computer when you turned it off when it was starting up. I did that to a laptop once.

But it was locked up, what else I supposed to do?

@Lukeweizer said:

@Dagbiker said:

I bet you fucked up your computer when you turned it off when it was starting up. I did that to a laptop once.

But it was locked up, what else I supposed to do?

Computers, its a lose-lose situation.

@MrKlorox said:

@Lukeweizer: ...Either way, you're probably going to need to spend money to fix it.

That's what I didn't want to hear. My internal card produced the same issues. I'll bring it to a repair shop.

@Dagbiker said:

@Lukeweizer said:

@Dagbiker said:

I bet you fucked up your computer when you turned it off when it was starting up. I did that to a laptop once.

But it was locked up, what else I supposed to do?

Computers, its a lose-lose situation.

Tell me about it. That's why I was so scared to buy/ build one for so long.

@MrKlorox said:

@Lukeweizer: ...Either way, you're probably going to need to spend money to fix it.

That's what I didn't want to hear. My internal card produced the same issues. I'll bring it to a repair shop.

What are your specific PC specs?

EDIT: It could be something as simple as reseating the heatsink on your CPU if you built the PC yourself. If you have a 7870, I'm guessing you also have a fairly newish computer. RMA the bad parts and you won't have to spend a ton of money to get it fixed.

@Lukeweizer said:

@MrKlorox said:

@Lukeweizer: ...Either way, you're probably going to need to spend money to fix it.

That's what I didn't want to hear. My internal card produced the same issues. I'll bring it to a repair shop.

That sucks man. Sounds like it'll be a bigger headache than simply replacing a graphics card. Good luck!

What are your specific PC specs?

EDIT: It could be something as simple as reseating the heatsink on your CPU if you built the PC yourself. If you have a 7870, I'm guessing you also have a fairly newish computer. RMA the bad parts and you won't have to spend a ton of money to get it fixed.

@Lukeweizer said:

@MrKlorox said:

@Lukeweizer: ...Either way, you're probably going to need to spend money to fix it.

That's what I didn't want to hear. My internal card produced the same issues. I'll bring it to a repair shop.

@Dagbiker said:

@Lukeweizer said:

@Dagbiker said:

I bet you fucked up your computer when you turned it off when it was starting up. I did that to a laptop once.

But it was locked up, what else I supposed to do?

Computers, its a lose-lose situation.

Tell me about it. That's why I was so scared to buy/ build one for so long.

@MacEG:

I have built my own PCs for a long while and have had very minimal problems, but you also have to know how to fix it when it breaks. I would be very careful taking it to a repair shop. I worked in the Geek Squad for about 5 years and they charge a lot for very easy fixes you could find out on your own. It might take you longer, but you would also save a good deal of money.

We would often look at a computer and see if it's even worth spending time on and tell the customer on the spot if it was the processor. So make sure they're not trying to just get money out of you.

I know this is not an ideal situation, but sometimes it's honestly cheaper to just buy a new PC, so don't put the thought out of your mind. Knowing you badly want to play the game this weekend might make you eager to dump money into, but again be cautious of repair shops, they'll eat you alive.

MacEG is correct it could be something easy like reseating (removing the item and putting it back in, with possible can-air cleaning).

Hope it turns out well for you.

@Lukeweizer said:

UPDATE: After some of your recommendations, I tried plugging my monitor into the motherboard's graphics card and I received the same issues. Seems like it might be something more serious than the graphics card?

If you're not against opening your case, try this.

Pull out the RAM. Boot the computer up. You should get a series of beeps. It means the computer has turned on, done its power on self test, and detected it has no memory. If you get this, one of those memory modules may be bad. I've had a few memory modules go bad with no indication on POST that it's bad. The computer just didn't boot. Just replace the memory modules. They're pretty cheap nowadays. I do suggest looking at 1.25 or 1.35v DDR3 modules.

You mentioned you plugged the monitor into your onboard graphics. Did you remove the Radeon card first? When you plug in a video card, it will disable your onboard graphics.

The unfortunate issue with the state of PC hardware and software is that it locks like that when one device is going bad and misbehaving (which is good!) but often fails to tell the user which of numerous devices installed need to be replaced. If you have the time I too would recommend pulling out and/or swapping components with "spares" to try to eliminate which device is going bad. Start with the RAM then pull out the stuff in the expansion-PCI slots and then pull out the video card. The idea isn to Diablo 3 to see if you can get duplicate or eliminate the behavior to figure out which part is broken.