I recently had an issue where a Power Supply stopped working and I sent it back to Thermaltake under warranty for a replacement. (kudos to them for ease) and They sent me back a heavier duty model as the replacement. What followed next was a year of issues. I finally diagnosed that the powersupply worked fine except under high heat and load conditions. If both conditions were met the computer would shut down and not turn back on for about 1 hour or more. I finally just used a junk powersupply and it has been working fine ever since. The original one was 600W replaced with a 750W model finally replaced with a 500W junk model. Has anyone else encountered this kind of problem? I am also interested to know if anyone would have a technical reason for this behavior to occur.