iMacs (Mid-2007) [#3]: More on FireWire target disk mode not working; fixes

We continue to report on significant issues with the newly released Mid-2007 iMacs and FireWire target disk mode. As previously reported, problem reports fall into two groups:

1. Other Macs (usually older models) are not recognized at all when connected via FireWire target disk mode to the new iMacs
2. Transfers that occur over a FireWire target disk mode connection (particularly system migrations) fail part-way through

Update firmware It appears that in some cases, outdated firmware may be disallowing older Macs from being seen in FireWire target disk mode from the new iMacs.

Apple Knowledge Base article #25773 states:

"[...] You'll need a FireWire cable to connect the two computers together. The Assistant offers to transfer (or "migrate") data from your older computer when you turn on your new computer for the first time. Make sure the older computer's firmware is up-to-date first."

Another Knowledge Base article, #304393, states:

"Some Intel-based Macs can become unresponsive while being used in FireWire target disk mode for long periods of time. [...] This behavior can be corrected with a firmware update to the computer that becomes unresponsive while in Target Disk Mode."

You can generally find firmware updates for your Mac model by going to Apple's download page and searching for your model's name along with the word "firmware."

Verify disk of problematic Mac We've received some reports indicating disk corruption and other drive issues can prevent proper transfer via FireWire target disk mode to the new iMacs. A reader writes:

"I also had a problem using the migration assistant to move data over from my Powerbook G4; the connection would get lost or freeze up part way. Turns out it was my Powerbook - the disk had a couple of minor problems with the volume so I had to fix permissions and then verify/repair the disk first and then the transfer worked like a charm. Possible the iMacs are really touchy with the quality of data coming over?"

Launch Disk Utility, located in /Applications/Utilities and use the Verify button to check for disk errors. If any are found, startup in Safe Mode by restarting your Mac by holding the Shift key, then restart again. Automatic disk checking and repairs are completed when the system is booted in Safe Mode.

Older Macs not supported? Meanwhile, some users are apparently being told by Apple that some older Macs are no longer supported with regard to FireWire target disk mode when used in conjunction with the new iMacs. One reader writes:

"I was told by Apple target mode no longer works with older macs. I have a G4 Quicksilver 933MHz and it failed to work. My new Macbook worked fine."

Feedback? Late-breakers@macfixit.com.

Previous coverage:

• iMacs (Mid-2007) [#2]: FireWire problems: Target disk mode and others (cont.); screen issues
• iMacs (Mid-2007): Problems with FireWire target disk mode; Condensation under glass

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