Screen saver not working. Ruined iMac!
Upgraded iMac to Mountain Lion a couple of weeks ago. Screen saver was working well until Sunday or Monday. Did not know! It was working before. The screen now has burn marcs! Ruined! Screen saver still not working except forced with hot corner. Furious! Tried permissions, restart with OC p r. Is there any way to fix this? And the screen? Took great care of this iMac and now because what seems like a bug from Apple, it's ruined.
iMac, OS X Mountain Lion (10.8.2)