FireWire connection dropouts: more fixes

Wednesday, June 18

After the installation of software updates, the FireWire ports on various Mac models may cease to properly function, not recognizing devices or exhibiting other issues. For some users, this has occurred with printer driver updates and for others it has occurred with the latest QuickTime update. One MacFixIt reader reinstalled Leopard and the problem still occurred.

The problem has persisted through several Leopard OS updates. Sometimes it knocks out all firewire connections, and other times it just seems to affect FireWire 400 ports only, leaving FireWire 800 ports working until the FireWire 400 ports are given significant load:

Fixes

Reset the FireWire controller Shut down the computer and unplug all peripheral devices, and let the computer sit for 3-5 minutes. Then start the computer back up and plug in the peripheral devices again, one at a time.

Quit processes Launch Activity Monitor and force quit these processes:

• socketfilterfw (this is the computer firewall)
• SystemUIServer (this should restart after quitting)

This worked for one user, who regained functionality of his FireWire 400 ports after quitting these processes. Since the first process listed is the FireWall, it could be that the firewall is interfering with the FireWire bus, since FireWire can be used for networking. People might try turning off the firewall in the "Security" system preferences, or removing the FireWire ports from the "Network" system preferences.

Reset the computer's PRAM, fix permissions, and other standard procedures If nothing else works, reset the PRAM and use Disk Utility (located in /Applications/Utilities to run routine permissions fixes on the boot drive. It may be that the FireWire port is broken, but these standard fixes might help before taking the computer in for servicing.

In order to reset PRAM/NVRAM, shut down your Mac, then start it back up while immediately holding the following keys: Command, Option, P and R. Hold the keys down until the computer restarts and you hear the startup sound for the third time.

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