My KK266R with an Enermax 651 power supply has worked flawlessly for weeks until this morning. I pushed the on-off button and nothing happened. I fiddled with the power supply connector to the motherboard. After I disconnected and reconnected the plug to the MB, I pushed the on-off button and the power supply came on. The computer booted and ran fine. I did a shutdown and pushed the on-off button again. Nothing happened.....again. I disconnected and reconnected the plug to the MB and pushed the on-off button. The same thing happened as the first time, the computer booted up and ran fine. What a pain!!!!! I do not believe the problem is the power supply, but rather the connector to the MB. Any other thoughts what the problem may be??? Thanks.