[ZLS]

    Hello,

    My iMac has started to go dark; the screen goes black but the audio is not affected.  This does not seem to follow any set pattern

but once it starts it continues until I shut down my computer for hours. 

   Any suggestions as to the cause, and/or fix would be greatly appreciated. 


                                                                              Thank You

[Blackmore]

The guys over at apple discussions say to completely unplug everything; power, usb, hard drives, etc. and wait for at least 15 seconds.  It's called a SMC reboot.  If that doesn't cure the problem the say it is probably a bad inverter.  That is for the older iMacs, not the newer LED models.  If it is a square box iMac, some of them are really easy to take apart and fix.  My new iMac looks to be impossible.  Good luck and start looking over at Apple boards to get some more ideas.