My iMac is constantly crashing

Hi. I have a mid-2011 27-inch iMac, 16 GB RAM. 1 TB hard drive, one-third full. Mavericks. My computer is constantly crashing. Sometimes every few hours, sometimes every few minutes. Disk Utility says my hard drive is ok. I tried deleting all start-up programmes in LogIn. That did not make any difference. I booted and then opened only Apple Mail and it still crashed. If I boot in safe mode, it works okay. I attach a problem report. I don't know how to read these things, but I see references to "kernel," so I suspect that could be the problem. The other thing I thought of doing is to disable or remove all Firefox extensions.

I don't see any attachment. Let me try again.

View attachment Problem details and system configuration.doc

Did you upgrade the ram since purchase?

- Nick

No, I have not upgraded the RAM since I bought the computer. I now have a theory about what is ailing my computer. I think it has to do with the external drives I have connected (there are usually six or seven), most of them on one large usb hub (Belkin, own power supply). I suspect that the plug of the hub was loose in its electrical socket. Or, there is something wrong with the connections between one or more of the drives and the hub. Or, there is something wrong with a particular drive. I am trying to sort it out. Stay tuned.

dgarmaise said:

No, I have not upgraded the RAM since I bought the computer. I now have a theory about what is ailing my computer. I think it has to do with the external drives I have connected (there are usually six or seven), most of them on one large usb hub (Belkin, own power supply). I suspect that the plug of the hub was loose in its electrical socket. Or, there is something wrong with the connections between one or more of the drives and the hub. Or, there is something wrong with a particular drive. I am trying to sort it out. Stay tuned.

Click to expand...

External devices can sometimes cause kernel panics. Just unplug the whole thing...and see if that helps.

- Nick

Think you are spot on with the Belkin hub.

Try running with the hub and external drive disconnected. For my iMac much prefer an OWC FW800 Mercury Elite Pro mini.

Yes, indeed, the iMac works fine with all external drives disconnected. I think it was the loose plug on the Belkin hub; it was loose where the plug enters the electrical socket. There were clues that I failed to pick up on: every so often an external drive would "disconnect itself." I don't think the hub per se is a problem. I re-connected the hub to the iMac, after fixing the loose problem, and I started adding back the external drives, one every few hours. Everything is reconnected now and I am not having any problems. Regarding the OWC FW800 Mercury Elite Pro mini, what is it exactly? It looks like a drive or a drive enclosure rather than a hub. I live in Thailand, and I am pretty sure I'll not be able to find it in the stores here. Thailand is the land of cheap knock-offs; I was "lucky" to find a Belkin hub amidst all the cheap and useless hubs for sale. It is very hard to buy a genuine DVD movie or concert here what with all the pirated stuff floating around. I suppose I could order the OWC online, if they will ship to Thailand. Thanks for all your help!

It is a caddy with a 500GB SATA II drive. I removed the drive and popped a OCZ SSD for speed. I live in Australia and OWC are the best option and even with USPS Air Mail are miles cheaper than local sellers.