Hi, Basically, when i do anything to strain my GPU even the slightest, my pc completely crashes as if power was lost to it. To keep things simple and easy to follow im going to list all the things ive tried, or important things. This way you can see what ive tried or use for example without reading lengthy paragraphs. - Specs: Radeon x1800xt Antec Truepower 550w asus a8n32-sli deluxe 3 sata drives 1 dvd-rw 2x1gb corsair 350LL pro RAM athlon 64 3500+ if you want other or more detailed specs let me know - highest temperatures monitored before crashes: cpu: 35C MB: 32C HDD's: 38C GPU: 55C - GPU was working 100% fine on previous dfi infinity nf4 motherboard. - PC is 100% stable as long as i dont do anythign to even minutely stress the GPU. i can watch movies, browse the web etc all fine but 15 seconds of a game or the ATI artifact scanner and it crashes. - with the side panel of the case on, the pc crashed during windows installing within 2 minutes, however i have not tried it with windows installed, while booted i have the side panel off and a big desktop fan almost touching the components. I'm really tired so cant think of anything else right now. My only ideas are that certain parts of the card are overheating, which the sensor is not picking up due to being far away, or the card got damaged during changing MB, or the MB is damaged in someway, or perhaps (please god be this)the bios is not set up right. Thanks for reading and i appreciate every last bit of help anyone can give.