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Troubleshooting Mac OS X 10.3.x (#17): Resetting the PMU for FireWire 400 problems; iPod preferences not sticking; DNS; more

Troubleshooting Mac OS X 10.3.x (#17): Resetting the PMU for FireWire 400 problems; iPod preferences not sticking; DNS; more

Resetting the PMU for FireWire 400 problems We are now hearing reports that a workaround we previously noted for fixing non-functional FireWire ports under Mac OS X 10.2.4 may also be applicable for systems that lost FireWire 400 functionality (no devices will operate) after installing Mac OS X 10.3 (Panther).

The workaround involves resetting the PMU (Power Management Unit), which performs the following tasks:

  • Tell the computer to turn on, turn off, sleep, wake, idle, etc.
  • Manage system resets from various commands.
  • Maintain parameter RAM (PRAM).
  • Manage the real-time clock.

In order to reset the PMU, you will need to disconnect power (and all other external devices for good measure), open the case - this workaround is specifically for most desktop Macs - , and press the PMU reset once. Pressing the rest button more than one time could have bad consequences, like causing the PMU to no longer operate properly.

Apple offers the following warning, however, about meddling with the PMU: "Be very careful when handling the main logic board. Remove the battery when handling the logic board so the PMU is not affected. The PMU is very sensitive and touching the circuitry on the logic board can cause the PMU to stop responding. If the PMU stops responding, the battery life goes from about five years to about two days if the PMU is not reset." [Additional instruction can be found in Knowledge Base article #95037]

It should be noted that there are a variety of issues apparently causing FireWire failure under Mac OS X 10.3 (Panther) including the FireWire 800 issue officially acknowledged by Apple and drive/controller manufacturers. This workaround is apparently useful in an unrelated scenario that has cropped up in previous incremental Mac OS X updates.

iPod preferences not sticking Several users upgrading to Mac OS X 10.3.x have found that their iPods are no longer capable of remembering preferences set through iPod, such as which playlists to synchronize.

MacFixIt reader Brian Romanchuk writes "Ever since upgrading to Panther, I've noticed that I can't change my iPod preferences. When my iPod has mounted and finished syncing, I choose the preferences and try and deselect a playlist that I have set to synchronize. It deselects and the dialog box hangs there for about 10 -20 seconds and then disappears. No updating takes place. When I bring the iPod preferences back up again nothing was changed. Same holds true for trying to switch on the Firewire Disk option. I've tried trashing all the preferences related to iTunes and ipod and nothing works."

One workaround for this issue that appears to be working for some is as follows:

  1. Perform a "Restore" process (erases the iPod's hard disk and restores the device to its original factory condition) using the iPod Software Updater application.
  2. Go to iTunes and access the iPod preference pane. Check the box marked "Enable Firewire Disk Use" (not check by default) and leave it check.
  3. Synchronization should now occur normally until you uncheck the "Enable FireWire Disk Use" option.

Note that without performing a "Restore" process, no preferences - including the FireWire Disk Use option - will stick. It seems that after a "Restore," the iPod preferences will be recognized for one synchronization, giving you a chance to enable the FireWire Disk Use option and leave it on.

Also, note that while the FireWire Disk Use option is in effect, your iPod will mount like any other volume, and be subject to a "Device improperly removed" error message if disconnected on the fly.

More on DNS resolution problems Yesterday we noted problems resolving DNS (domain name server) addresses under Mac OS X 10.3.x and suggested two possible workarounds:
  • deleting DNS entries from the System Preferences Network pane, restarting, and then re-entering the information.
  • Navigating to /Library/Preferences/SystemConfiguration and deleting the files NetworkInterfaces.plist, and preferences.plist

Now MacFixIt reader Udo Ludtke reports that simply entering his ISP's virtual (plain English) server name into the System Preferences' DNS field resolved the issue:

"I had the same problem. I had no entry in Preferences->Network->TCP/IP tab->Search Domains box. This worked fine in Mac OS X 10.2.x, but not in Panther (Mac OS X 10.3.x). Once I entered the domain name of my ISP, e.g., into the Search Domains box, the intermittent can't-find-server problem is gone. It appears that for some reason Panther refers to this entry now and then."

Microtek scanner statement Microtek has issued us an updated statement on Panther support for its line of scanners (for more information on troubleshooting scanners in Mac OS X 10.3.x, see the section of our special report entitled "Solving Scanner Problems").

The company says:

"Microtek is committed to the Mac community and is currently in the process of developing full Panther compatible drivers. In the meantime, we have updated our Panther workaround instructions for ScanWizard Pro and Pro TX that was recently posted.

"This workaround will support scanners which were previously supported under Mac OS 10.1.5-10.2.8. Unfortunately this work-around will not support SCSI Only scanners. Please note, although this solution has worked for most users; however it has not worked for all. Please visit for the latest on Panther support and compatibility information. If you have further questions please call our Macintosh Consultants at 310-687-5922 for further assistance."

[The published workaround is a step-by-step process that involves extracting and deleting SCSI components of the Support Bundles folder]

All the updated Panther information can also be viewed at

Virex scanning problems There is a problem being reported more often in recent days where (under Mac OS X 10.3.x.) Virex will begin to scan you computer, abruptly stop and say it's complete when in actuality it's only scanned a few files.

MacFixIt reader Katie Floyd writes "There is some speculation on the McAfee's site among users that it is a problem with Microsoft Excel files. I have been unable to verify this myself other than to say I have a few Excel files on my computer and I am having the problem. I don't yet know if they are related or not."

Floyd's report is consistent with other readers, who have had Virex scanning fail when traversing the home directory, where Excel files are likely to reside.

If you are having this problem with frequency and do not have any Excel files, or have any other information, please drop us a line at

  • offers
  • #95037
  • "Restore"
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