[Dork.]

Hello! I have an ailing "sunflower" G4 iMac that I need help diagnosing.

When it was brought to me to help, it wasn't booting from the hard drive (displaying the ? icon on boot) and I was told it was making a "clicking" sound. Sounds like the hard drive died, right?

We managed to find a cheap replacement IDE drive and I replaced the "failing" drive (not a simple feat in this iMac). I had to go into Open Firmware to open the CD tray and put a system disc in, but when I rebooted I found it wouldn't boot off the CD drive, either.

Not to worry, I thought: maybe the CD drive is toast, too, so I'd just have to re-boot in FireWire Target Disc Mode and reinstall the OS from another (PPC) Mac with Firewire: I've done this before. Only when I connected up the iMac, I couldn't see the FireWire target drive, and the "dancing" FireWire Icon on the iMac while in Target Disc Mode stopped dancing. (System Profiler reported that a FireWire Target Mac was attached, but did not report a disc drive attached to it.) Now, I'm suspecting that either the new drive is bad, or I have bigger problems.

So, I boot into Open Firmware again. I try to eject the CD, and it told me that it couldn't find the CD device. D'oh! On top of everything else, I need my disc back!

Today, I'm going to check both drives, to ensure that the first drive has really failed, and the replacement wasn't DOA to begin with (luckily, we bought two replacements, so I have an alternative is the drive was DOA.) Beyond that, what's worthwhile to do?

The only idea I have is to somehow use Open Firmware to report on what drives it thinks are connected: if it doesn't see any, then perhaps the main board HD controller has failed. I might be able to put the drive in an external Firewire enclosure and get the thing to work, but who knows what else is wrong with the main board?

Sorry for the rambling post. Any thoughts on what else I might do next?

[Eug]

Sounded like a hard drive issue, but before you sealed it all back up, did you set the drive jumpers correctly, clean out all the dust in the iMac, and make sure all the RAM and cables were seated correctly?

The drive jumper settings will be on your original defective drive. If it is set as master, set your replacement drive as master. If it is set as slave, set it as slave. (The optical drive will have the opposite setting.)

Firewire Target Mode will not work if the drive is jumpered incorrectly. In fact, probably nothing will work if the drive is jumpered incorrectly.

I'm getting conflicting info on the internet for the proper jumper settings. Some say HD slave and some say HD master. I was under the impression that FW target mode needs the HD as master, but I'm not sure if this is true in all cases. In your case just match it up to your old drive's settings.

[Dork.]

Jumpers! I forgot about those, it's been so long since I've dealt with IDE drives.
I think it ought to be set to Master. The new drives we bought were refurbs, so there is every possibility they are set to slave. I will check....

The rest of your advice is sound, bit I'm an old pro at opening these G4's now, so I did all that other stuff.

[Waragainstsleep]

From memory some of those G4 iMacs had slave drives and some had masters. There may even have been the odd one set to cable select which was very unusual from Apple.

[reader50]

If all else fails, reset with the CUDA button. I've gotten odd behavior a few times after upgrades until I gave it a reset.

Did you check the battery voltage while you had it open? This isn't the problem since you reached OF. But your iMac is old enough the battery will be on it's last legs.

[Dork.]

Originally Posted by Waragainstsleep 

From memory some of those G4 iMacs had slave drives and some had masters. There may even have been the odd one set to cable select which was very unusual from Apple.

Bingo! The old drive was set up with Cable Select. Set the new drive to Cable Select, and now all is peachy. I didn't think anyone ever used that setting.

Thanks, everyone, for your help!

[Eug]

Excellent.

I never knew Apple ever used cable select either. IIRC, my G4 iMac didn't. You learn something new every day.

[reader50]

The earlier G4 PowerMacs did not support CS. The later ones did, and tended to use it. The non-PowerMac G4s tended to be current with the later PMs.