PowerMac G5: More on fan errors; Freezes and M-Audio Delta 66

Yesterday we reported on strange errors in /var/log/system.log since updating G5s to Mac OS X 10.3.3, namely:

"IOPlatformControl::registerDriver Control Driver AppleK2Fan did not supply current-value, using default"

Apple Knowledge Base article #86492 contains some interesting information about G5 fan error messages:

"Two error codes in Apple hardware Test (AHT) 2.1 may indicate an error when there is no error:

• 2FAN/4/x: Fan For BACKSIDE: This error code usually means the fan behind the drive bay has failed. This fan is a "blower" type fan, located behind the drive bay fan. The drive bay fan is located between the hard drive and the SuperDrive.
• 2FAN/4/x: Fan For SLOT: This error code usually means the slot fan has failed. The slot fan is located in front of the PCI slots near the front of the computer and just under the SuperDrive.
• 2STH/x/x: xxxx AMB: (The "x" will be a number and "xxxx" will identify a sensor.) This error code usually means an ambient thermometer sensor has failed.

"When you see "2FAN/4/x: Fan For BACKSIDE" or "2FAN/4/x: Fan For SLOT", there's probably nothing wrong with the fans."

Freezes and M-Audio Delta 66 MacFixIt reader Tom reports a problem with his G5 and the M-Audio Delta 66 card for which we are seeking confirmation "For the last few weeks, I've noticed numerous crashes while playing 3D games such as Halo, Unreal Tournament 2003, or Jedi Academy on my G5 dual 2.0Ghz system.  Typically, after only 1-5 minutes of gameplay, the screen would turn black and the last couple seconds of audio would play over and over in an endless loop.  If I let it sit like that for long enough, I'd come back to find it no longer playing any audio, and all of the fans running at full speed.  There was no way to quit the crashed program other than holding down the power button for 5 seconds.

"I finally discovered that the problem went away when I pulled out my M-Audio Delta 66 board that was in one of the PCI-X slots.  (This is one of the cards that had been sent in to M-Audio for modification to make it PCI-X slot compatible in the G5.)

"Before I did this, I tried removing the Delta 66 audio drivers, thinking maybe they were causing a problem - but that made no difference.  It seems to simply be an issue of the card physically being installed in the G5.

"I emailed M-Audio tech support about this issue, but haven't heard anything back from them yet.  My next plan is to experiment with putting the card in different slots, to see if that helps.  (Perhaps, Apple has address lines that are shared between the video card slot and one of the other PCI-X slots, and I happened to have the Delta 66 board in this "shared slot"?  I know I've seen similar situations on Windows-based PCs before - where cards had to be moved to other slots before things would work normally.)"

Feedback? Late-breakers@macfixit.com.

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