Problem starting up 2011 21" iMac
I usually let my iMAC go into sleep mode when not using it, however recently and periodically when I click the magic trackpad to start using it again it will show the password screen for about 1 second then go back to a blank screen, however I can hear that the disc is working and the machine is alive. I then usually have to click the trackpad about 3-4 times, waiting each time about 2 minutes before eventually it will hold on the password screen and then let me start typing in the password and start using it.
Does anyone have any ideas as to what this could be..?? and, more importantly, what I can do to stop it happening..?