Hi everyone, I hoping that somebody with much more Apple experience than me can help please? My friend has a really nice iMac 27" late 2009 http://forums.macrumors.com/attachment.php?attachmentid=450338&stc=1&d=1386247434 that has developed a very strange issue. He can be working away with a large Photoshop file and boom the screen will go dark (see vid). Sometimes he can recover by pressing sleep and then touching the space bar brings everything back but sometimes not. It can last half an hour or maybe only 5 mins but it will start doing this annoying thing at some time or another. Here's a video of the problem: https://vimeo.com/80889318# I have asked in a couple of other forums where I spend some time but I've been advised that this forum is probably my best bet for getting some help. Here are a couple of links to those forums, if people don't mind reading them to get a clearer picture of what is going on and what I've done to troubleshoot the issue. http://www.avforums.com/threads/apple-27-imac-late-2009-is-it-dying.1836684/#post-20014678 and http://forum.osxlatitude.com/index....ckingtosher-in-need-of-help-with-imac-please/ I'm no expert in iMacs but I'm leaning towards hardware issue, maybe the LVDS cable or maybe the panel itself but who knows. Only having 3 leds showing on the logic board is also strange too. Could it be the logic board all along? Help please and many thanks in advance. Update: I've just gone into Disk Utility and I've noticed that SMART is reporting impending disk failure....please backup your data! Could that be having an impact on the display or is that something else going wrong too?