My computer starting randomly shutting down without warning while I was playing games (after 6 months of smooth sailing). This quickly progressed to shutting down when I wasn't playing games to not even being able to boot up completely before it shuts down again. Initial Thoughts: Dust Power Supply So I layed the unit down, took off the cover and dusted it all out (including the CPU heatsink/fan etc.). While the unit still lay on its side, I powered it back up and everything seemed to run fine. I booted up a game and everything was running fine when I decided to stand the computer back up, once I had it 90% upright, it shut down again. I am having no problems if I leave the computer laying on its side. What is going on?? It's shutting down without any error messages. Just shuts completely off as if the power has been cut off. The motherboard light stays lit. CPU temps are stable between 43C and 48C. This is a custom computer I built myself, but would consider myself an amateur. I would appreciate any input before I start fiddling with it and messing everything up.