Apple OS X 10.5.7 overheats some Macs

Robert Black was right. OS X 10.5.7 adversely affects the internal heat management of some iMacs (and apparently also some MacBooks), causing the machines to overheat. Overheating, in turn, leads to such problems as freezes during iCal sync; freezes during iTunes sync; and the inability of attached hard drives to complete a backup.

Blah blah

I confirmed this by installing smcFanControl and watching my Mac get hotter and hotter as it tried to complete a SuperDuper backup. Disk Utility confirmed nothing was wrong with the attached drive. Swapping cables proved a faulty cable was not to blame for previous failed backups. Maddeningly, the backup got within 4GB of completion before locking up due to the overheating of my iMac.

Not every iMac or MacBook is affected. It probably varies by factory run and by model. (My MacBook Pro, for instance, is fine.) Third-party stuff and Migration vs. Tabula Rasa System Install seems to have no bearing on whether or not your Mac will choke on the update.

Since even running smcFanControl at settings recommended by Robert Black and others doesn’t cool the iMac enough to finish a backup or verify the quality of the attached drives, it may not make sense to replace my external hard drives (as new drives will likely also fail as the iMac overheats during backup).

With smcFanControl in place, I can use my iMacs but not back them up.

Apple needs to release an update that fixes the hardware problems this one created.

(And someone else needs to install it before I do.)

[tags]OSX10.5.7, bugs, Apple, Macintosh, update[/tags]

Quick survey on OS X 10.5.7 bug triggers

Update: see OS X 10.5.7 overheats some Macs.

Fellow Mac users, let’s see if we can isolate the triggers of the OS X 10.5.7 blues. If we learn the cause, others may know whether it’s safe for them to update, and we may provide Apple’s engineers with a clue on how to fix the problem in a subsequent update.

Theory 1: Migration Assistant

My affected iMacs have systems that were migrated. That is, when I bought the machines in December 2007, after running them for a while as-is to ensure that they worked properly, I ran Migration Assistant to bring over applications, preferences, network settings, and so on from my previous work machine (a non-Intel white powerbook).

Blah blah

Theory: Possibly OS X 10.5.7 update becomes unstable in the presence of a leftover something migrated from an older system.

Test: If you’re suffering from the 10.5.7 blues, did you run Migration Assistant on the afflicted machine? Did you migrate from a non-Intel machine?

Theory 2: Third-Party Stuff

When something goes wrong with a Macintosh update, a third-party add-on is often the trigger. Here are the add-ons on my sufferin’ iMacs:

Items marked “removed!” were my initial suspects. After the update, iTunes froze on sync. I reckoned the iLike plug-in was to blame, and after removing it, was able to sync again for a while.

Then the Mac froze during an iCal sync, so I removed MenuCalendarClock.

But removing these little guys didn’t fix anything. Soon enough, even without these add-ons, the Macs were freezing during iTunes sync and during MobileMe iCal sync. Eventually they froze on any app, doing anything. (Only to inexplicably resume normal operation again for hours at a time. But enough of this.)

And you? If your Mac is misbehaving after running OS X 10.5.7 update, are any of these add-ons on the machine?

[tags]OSX, bugs, OSX10.5.7, 10.5.7, apple, software, updates[/tags]