Of late - I don't how late - my iMac G5 has developed a nasty habit. AFter being turned on, the fans will very slowly increase their speed, first the System and Hard Drive fans, then the CPU fan. They appear to settle at a speed some several hundred RPM above the minima.
This appears to be independent of:
User
CPU usage
temperatures
/Library/Preferences
Hardware monitor shows the temperatures falling to their minimum levels, while the fan speeds continue to rise.
Also, the machine never wants to go to sleep any more.
Tomorrow I will try an archive-and-install to see if that helps. In the meantime, please send a postcard with suggestions to the usual place.
Daniele
On 2006-02-17, D.M. Procida real-not-anti-spam-address@redacted.invalid wrote:
Of late - I don't how late - my iMac G5 has developed a nasty habit. AFter being turned on, the fans will very slowly increase their speed, first the System and Hard Drive fans, then the CPU fan. They appear to settle at a speed some several hundred RPM above the minima.
If it's a rev. 1, take the back off and check for leaking/bulging capacitors.
D.M. Procida real-not-anti-spam-address@redacted.invalid wrote:
Of late - I don't how late - my iMac G5 has developed a nasty habit. AFter being turned on, the fans will very slowly increase their speed, first the System and Hard Drive fans, then the CPU fan. They appear to settle at a speed some several hundred RPM above the minima.
This appears to be independent of:
User CPU usage temperatures /Library/PreferencesHardware monitor shows the temperatures falling to their minimum levels, while the fan speeds continue to rise.
Also, the machine never wants to go to sleep any more.
Tomorrow I will try an archive-and-install to see if that helps. In the meantime, please send a postcard with suggestions to the usual place.
Daniele
Acquaintance of mine had a problem like this with his rev 1. Was the straw that broke the camel's back that led to this troublesome rev 1 being replaced with a shiny new rev 3 under guarantee.
D.M. Procida real-not-anti-spam-address@redacted.invalid wrote:
Of late - I don't how late - my iMac G5 has developed a nasty habit. AFter being turned on, the fans will very slowly increase their speed, first the System and Hard Drive fans, then the CPU fan. They appear to settle at a speed some several hundred RPM above the minima.
Anything to do with this?
http://docs.info.apple.com/article.html?artnum=303079
Please let me know how get on with this problem.
All the best, Tom
Tom Warner tom@redacted.invalid wrote:
Of late - I don't how late - my iMac G5 has developed a nasty habit. AFter being turned on, the fans will very slowly increase their speed, first the System and Hard Drive fans, then the CPU fan. They appear to settle at a speed some several hundred RPM above the minima.
Anything to do with this?
http://docs.info.apple.com/article.html?artnum=303079
Not that, unfortunately.
It's a second-generation 20" G5.
The problem is very, very weird.
Normally, when the CPU's working hard, the CPU temperature rises rapidly and falls just as rapidly, as does the fan speed for the CPU.
Sometimes though, and I don't know what triggers it, the fans speeds will creep up slowly in a parabolic curve. Leave it alone long enough and they will descend again, but I don't know yet how far (that's how slow it is). The rate of ascent and descent, once this behaviour has been triggered, seems to have nothing obviously to do with temperatures, so far as I can see.
On the other hand, it survives a restart, but is gone after a long sleep.
Daniele