Hi guys, not sure if this is the right forum to post this, but any help would be greatly appreciated! Recently, my computer began shutting off instantly when I was playing any particularly resource-intensive games (specifically Space Marine). Initially I had guessed it was overheating, so I cleaned out all of the components in my PC and restarted, but I was met with the same problem repeatedly. I had then assumed that the fault was with the PSU, so without any to spare, I ordered a new one. Upon arrival I put it into the PC, but it whirred noisily and smelled like burning. Clearly broken, I sent it back. A few days later I got a new one, put it in the PC and all was good, the PC got past the boot stage and I booted up Space Marine again, but once more, it broke down and shut off instantly after a few minutes of playing. I was pretty sure the power supply wasn't likely to have broken three times in a row, so I tried it in another PC and it worked fine. After that, I tried disconnecting each component in turn, ruling out (I think) the DVD Drive, BluRay drive, both Hard Drives and the Sound Card. I tried taking out my graphics card and replacing it with an old one of mine, an 8800gt, and the PC booted up. I was pretty sure that was fixed, because I could play games for a while with no issue. Eventually, however, it crashed again. Interestingly, whenever it does crash, I can't boot up for a short while, the fans whir for a second and then nothing happens. I'm totally out of ideas, so any help would be greatly appreciated!