Help me help her iMac boot from the install DVD.

April 24, 2009 9:49 AM

iMac G4 won't start from (iMac G4-specific) OS X install disk. But WILL start from the Apple Hardware Test CD. More details follow...

After years of successful Mac troubleshooting, and much Googling, I am stumped.

My friend's G4 iMac (swivel-neck monitor) won't start from its hard drive, so I am trying to reintall the OS. (I think the problem started when she tried to install an OS update which crapped out before completing.) The disk is the correct disk for the iMac G4; it came with the iMac. I tested the disk on my iMac G4, and mine boots from it just fine. It's not dirty or scratched.

So here's what happens.

-Holding "C" on startup: the optical drive sounds like it's being accessed, but after a few minutes it stops spinning and the iMac stalls at the gray Apple logo screen.

-Holding "option" on startup: I can choose the hard drive or the optical drive. The disk in the optical drive is recognized as a potential startup disk. Selecting to start from the disk causes the same symptoms as above.

-Booting from the Apple hardware test CD: Boots up with no problem. Hardware test finds no problems.

-Running fsck from open firmware returns a hard disk error (expected) but it can't fix the problem. Obviously, this should not prevent optical disk booting.

-Have zapped PRAM, plus many other startup tricks (safe mode, etc). The only thing I haven't done is reset the PMU.

-The only memory installed is the factory memory. And hardware test finds no problems with it.

My current thought is that the optical drive is faulty, unable to read the install disk (DVD) but can read the hardware test disk (CD). I've seem other reports of similar problems, but no solutions.

Any suggestions? Thanks!

posted by The Deej to computers & internet (10 comments total)

Possibly obvious, but this particular iMac does have a DVD drive, correct?
The earliest iMac G4s do not.
posted by kidbritish at 9:59 AM on April 24

I'm (pretty darn) sure it has a DVD drive. I can't double-check until after work, but that's worth checking.

But, if that's the case, the DVD wouldn't show up during option-boot as a viable OS X startup disk. I think.
posted by The Deej at 10:05 AM on April 24

I had a swivel-neck iMac have the optical drive problem you describe - some varieties of CDs and DVDs wouldn't read, while others would.

My recommendation for a reinstall is to boot the iMac into Firewire Target Disk mode, attach the machine to another Mac, boot *that* Mac off the restore discs, and do the reinstall that way. I've used this method to restore a number of machines with cranky optical drives.

(Hopefully the restore disks won't get cranky that you're trying to boot off another machine. You may want to find some retail OS install discs to have on hand as a backup.)
posted by Remy at 10:55 AM on April 24

Could be that there was a firmware update done to the machine and the original disks won't boot it up anymore.
posted by boomcha76 at 11:41 AM on April 24

Similar to what Remy has said, I haven't installed Mac OS X 10.4 or 10.5 from optical media in years. The ability to create a "tools drive" out of a relatively cheap Firewire HD is one of the keys to being a good and efficient Macintosh technician. For instance, all of my tools drives are configured this way:

• Partition 1 (10GB) = Mac OS X Installer (now 10.5.6 Retail)
• Partition 2 (20GB) = Utilities Boot disk with an up-to-date OS X install with all my favorite tech tools installed (DiskWarrior, Data Rescue, Stellar Phoenix, TechTool, Drive Genius, packet sniffers and Airport diagnostics, etc.
• Partition 3 (the remaining space) = Installers and Data store (for data recovery, etc.).

I've yet to meet a Mac that I can't boot with my tools CD. I keep it up-to-date (typically once a month) and I'm constantly trying out new tools as they come on the market. I generally have used APM (Apple Partition Map) instead of GUID, so I can stay compatible with older PPC Macs, but if you know you'll only be working on Intel Macs, I suppose you could just leave your formatting as GUID.

The time it takes for doing an Archive & Install on a system is cut from 45-60 min, to 10-15 min since the Firewire or USB bus is so much faster than the optical drive. Installations happen faster since you don't have to swap out optical disks. I can install Final Cut Pro Suite 2.0 in under an hour (60GB of data); if I were using optical media, it's a many hours long process.

Were I in front of this iMac, I'd completely give up on the optical media and resort to a Retail copy of Tiger, or at the very least, make an installer out of a FWHD and install from that. Hope this helps!
posted by mrbarrett.com at 12:08 PM on April 24

Sigh, must learn to preview.

"I've yet to meet a Mac that I can't boot with my tools CD" should read "tools HD", not CD. Sigh.
posted by mrbarrett.com at 12:10 PM on April 24

Thanks everyone so far!

mrbarrett: I may have a retail Tiger disk, so I'll try that first, then try Remy's target disk mode.

Also, mrbarrett: that's a ton of great info. Thanks! Alas, I am the "favor-doer" and not a paid technician, so I'll just have to use what I have on hand, and if that fails... we'll see. But I'll certaily file your info away for future use.
posted by The Deej at 1:25 PM on April 24

This question prompted me to write up a longer how-to article on creating a Mac Tech Utilities drive. Good luck! I hope you find it useful.
posted by mrbarrett.com at 7:45 PM on April 27

Thanks again mrbarrett. I have been out of town all weekend, and I'll be revisiting my friend's iMac tomorrow (I think). I have a retail Tiger disk and my own iMac G4 with firewire cable ready to take with me. I'll post a followup.
posted by The Deej at 8:21 PM on April 27

Followup: I was able to install from the Tiger retail DVD, but I had to reformat the hard drive.

Boomcha's answer is likely correct. mrbarrett.com's answer has a lot of great ideas for future reference.
posted by The Deej at 12:22 PM on May 24