My 2011 iMac started having this weird problem today. Basically, when i turned it off in the morning and left for work, it started turning itself on and off multiple times while i was away. When i got home, I tried turning it off, and it would turn itself on after anywhere between 1-2mins. The boot screen shows up and i would get the booting sound, then it would restart itself and do the same thing over again. I unplugged the power and waited for a while, then the imac turned on correctly, but as soon as i set it to sleep, it would fail to wake up. Now i can't even switch it on; the keyboard and mouse would lightup(third party ones) but nothing shows up on the screen and no boot sound. 2 seconds later the lights go off and it would try to restart again. Again, I have the 2011 i5 imac, with a samsung 830 SSD installed not long ago. Please help!