Hi guys, First time poster here so apologies if I don't do this quite right I have a late 2009 27" Imac. I'm a photographer and doing my biggest job of the year and whilst working in Lightroom my images suddenly became unresponsive and failed to work. I have Lightroom on my hard drive but my catalog and files on an external hdd. So I restarted and basically it told me that the catalog wasn't working and to choose another. After trying this a few times it now won't even open. Neither will iTunes or most apps. I've tried the disk verifications (that still seems to work). Safari was working but the keyboard has now stopped typing (mouse still working). I've restarted a few times and now have hit the stage where I'm outta ideas! Does anyone have any ideas for me before I pack it up and send it to the experts??!