Intel iMac partial (?) boot

I have a 17" iMac (early Intel, 2006) that will start to boot (Apple symbol, spinning cursor for about 5-9 revolutions, then just blue screen. Also cannot get the machine to boot from Install Disk or go into a Target Disk mode. I've tried all the usual resets, etc., and am about ready to conclude that it's got a serious hardware issue (owner has already written it off and bought a new one) and pull the HD (which is SATA), put it in my G5 tower and just try to recover some of the previous owner's files. Any thoughts as to an easier solution? The only easy way to get the HD out of this machine is with a cutting torch or a chainsaw.

Getting a blue screen on startup usually indicates that there is a startup (login) item installed that isn't compatible with the version of the Mac OS that you have installed. See these Apple technotes for suggestions on how to deal with the problem:

Mac OS X 10.6 Help: If you see a blue screen at startup

Mac OS X 10.6 Help: Eliminating incompatible login items

A blue screen is often remedied very easily by doing a Safe Boot:
Resolve startup issues and perform disk maintenance with Disk Utility and fsck

OS X Maintenance And Troubleshooting
Item #5

___________________________________________

Randy B. Singer
Co-author of The Macintosh Bible (4th, 5th, and 6th editions)

Macintosh OS X Routine Maintenance
OS X Maintenance And Troubleshooting
___________________________________________

If he can't get the machine to boot with the install media or from Target Disk Mode, it's not a login or startup item causing it. It sounds more like a dead hard drive or one that's seriously ill.

@rico567:

Like I said above, it's acting like the HDD has failed. And the only way you can remove it is by first removing the front panel and LCD to get inside. In order to do that, you'll need glass suckers and several special tools.

Follow the step by step instructions at iFixit: The free repair manual. Have your model number on hand. They also sell the tools you'll need if you don't already have them.

chscag said:

If he can't get the machine to boot with the install media or from Target Disk Mode, it's not a login or startup item causing it. It sounds more like a dead hard drive or one that's seriously ill.

Click to expand...

That's a good point. I thought about that.

But I wouldn't expect a failed or failing hard drive to consistently get stuck at the blue screen. Getting to the blue screen would normally indicate that the hard drive is working fine, but that it is hanging up at the point where it is trying to load the system software.

Note that Apple doesn't see the blue screen as normally being a sign of a failing hard drive, they see it exclusively as a sign of a software problem:
Mac OS X 10.6 Help: If you see a blue screen at startup

In any case, it's easier (and cheaper) to try the software fixes before going to the extreme of replacing a hard drive. If nothing else works, *then* its time to think about replacing the hard drive.

___________________________________________

Randy B. Singer
Co-author of The Macintosh Bible (4th, 5th, and 6th editions)

Macintosh OS X Routine Maintenance
OS X Maintenance And Troubleshooting
___________________________________________

As a thread followup, thanks for all who posted helpful suggestions.....but, in the final analysis, the problem will remain unknown.

In the end, updating OSX on the old machine online only resulted in a completely unbootable system (as described in the OP), and one that wouldn't boot from either the original Install Disk or from a generic Leopard Install Disk.

I ended up using a brute force method, disassembling the old iMac (thanks, "chscag" for the iFixit link- it was invaluable in accomplishing the disassembly), removing the HD, installing it in my old G5 tower, and moving the files that way. Turns out that the HD was fine (a 160 G Maxtor), and mounted automatically in my tower. Not a smooth migration, by any means, but at least the individual has all their files, except for one folder out of many, in which the files have all been split into resource & data forks, with the resource forks neatly placed in a folder. Still can't figure that one out.....

Also, I didn't mention in the OP that the user in question had already bought a new iMac, so the old system just exits as assorted parts.

I do think I have converted another user to the virtues of backing up.....

Great, glad everything worked out OK. Thanks for posting back.