I had a similar problem, except when I left it unplugged for some hours or days, it would eventually decide to turn back on. Some of the tech people at my work looked at the event logs and said that the problem appeared the last few times the computer had hibernated (as opposed to simply sleeping). I turned off the hibernate function (Run 'Command Prompt' as administrator, then type "powercfg.exe /hibernate off" and press the Enter key, exit the Command Prompt program), and the problem hasn't returned. I recommend waiting with it unplugged for a few days, and trying to turn it on every now and then until hopefully it turns on, then deactivating the 'hibernate' function as above. Hope this helps! Good luck!