Dear friends, I am in trouble. My iMac late 2009 has been misbehaving in the past weeks and things seem to be degenerating quickly. Please advice on what I could attempt. Since a few months ago the iMac, running 10.9.5) very infrequently hung meaning the screen would remain lit, the mouse pointer still moved, but no other response was obtainable. I had to push the power button for a few secs and power it down brutally. It usually came up apparently allright and could work for some more weeks, sometime months, without apparent problems. Lately the iMac did this a little more and a couple of days ago things became a lot worst. The boot remained stuck at various stages with the apple logo on grey background, sometimes the spinning disk, tried resetting PRAM, boot in safe mode and yesterday resorted to also reinstalling Mavericks. Yesterday the machine hung again, and this morning I tried to restart it but it seems stuck at the Apple with no other discernible outcome (then had to scram for work so will not be able to do anything further for the next 10 hours or so). Question a) If I manage to restart it, would looking at the logs possibly give away some clues ? (Yesterday I had a temperature monitor running and it did not show anything strange) Question 2) Would bringing the machine to Apple for such an elusive / not easily reproducible problem be worthwhile ? Question 3) If I cannot manage to spot anything strange is there something I might try out of past statistics you have ? Question 4) In the worst case are there any tradeback programs which could help me offset the cost of buying a new machine ? Question 5) I have a current TimeMachine backup of only an hour prior to the last crash. If I ever resort to having buy a new machine, could I use it to restore not only my data but also the installed Applications/Library even though it would be a different MacOS level or is it better to painstakingly reinstall everything from new ? Thank you very much for any help.