Power Mac G5 (June 2004) Firmware Update 5.1.8f7 (#5)

We continue to cover issues with sleep and excessive fan activity after installing the recent Power Mac G5 Firmware Update 5.1.8f7 (only for June 2004 Power Mac G5 models). The most common symptom of this issue is an unexpected, unresponsive blank screen accompanied by excessive fan noise.

Extra fan noise, but no increase in crashes For some users, application of the Power Mac G5 5.1.8f7 firmware update only increased the amount of fan activity, without the accompanying increase in crash frequency.

This phenomenon has occurred with firmware updates for other Mac models as well as incremental Mac OS X updates. In particular, PowerBook G4 12" owners found that, after installing Mac OS X 10.3.2, CPU and overall system temperature were significantly higher.

MacFixIt reader Frank writes "I just wanted to drop your team a short note that I upgraded the firmware to my stock DP 2.5 G5 yesterday and have seen a drastic increase in fan activity and fan noise.

"Since I received this machine, I would every now and then hear a soft muffled whir during light activity. After the firmware upgrade it's a whole different story. The fans come on repeatedly and appear to throttle up much farther, even all the way to full speed just using email and the web. I just scrolled down my own home-page and the fans now start whirring loud, where they never did in fact come on at all, that I'm aware of.

"I'm also under the impression that the fans are / may now in fact be running continuously, where they did not before, as my system does not appear to be as quiet. There seems to be continuous fan activity where before it could be as quiet as my cube with just 0-5% load.

"[...] Note that the fan / cooling issue is not accidently related to any heat in the house or near the system. Same house, same room temperature."

Out-of-the-box occurrence of the issue A number of users are experiencing this issue soon after unpacking their new or refurbished G5s -- reinforcing an earlier notion that this issue is not strictly caused by the 5.1.8f7 firmware update, though it certainly is a trigger in many cases.

Larry Angier writes "I had similar experiences out of the box with the refurb G5 Dual 2.0 that I bought as a refurb from Apple in early August. Crashed 13 times the first day. System went to 747 take-off mode a number of times (thermal runaway).

"First call to Apple and it was reinstall the OS from ground zero. No fix. Second call and the use of Garage Band pinpointed to a bad secondary processor. Time for a drop-off at the Apple store 60 miles away. [...] Ten days later it was on the road for me. Apple called three weeks later that the machine was ready.

"Picked it up. Logic board and both processors replaced. It worked much better. Then it was not waking from sleep. Called Apple and re-seated the video without success along with all the other little odds and ends to check out. Finally they sent me a new card and all was well.

"All is well only when I don't turn off the machine. Still hanging two to three times upon fire-up. Usually OK if coming out of sleep, though. This morning took about three to four restarts to get going, once into thermal runaway. Don't think it is a thermal problem since the G5 is in an unheated office and it is probably in the upper 50s lower 60s where it is sited."

Feedback? Late-breakers@macfixit.com.

Resources