G5 Random sleep, fan racing, red LED on

[emailjack56]

Problem with APPLE A1047 POWER MAC G5 DUAL 2.7GHZ 2GB ATI Radeon9650:

Random sleep, fan racing (single fan on hard drives), red LED on steady- not blinking.

Fan racing: just the fan cooling the HDs and it begins immediately on cold start (not heat related). All other fans appear to run normally. Temp. Monitor indicates all temps normal.

Sudden sleep: The G5 runs for a few minutes before winking out into sleep. In a few seconds, it comes back to life on its own. THen goes back to sleep. Also, easily re-awakes with a touch of the mouse.

I've read related posts but none that exactly match my issues.

Questions? Answers? Clues? Thanks in advance.

 

[Tyroler]

In OSX is a emergency Program,which,when it realises that the Computer is out of Control,rises the Fan to full Speed,to avoid Overheating.
Question is now,why out of Control.
I rekon the cooler is leaking and Logicboard will pass away if you dont fix it early enough.
But every Time booting brings you closer to a death Board and CPU due Wetness.

 

[emailjack56]

Okay to laugh...

The red LED and racing fan were due to....wait for it... I had the door off.
Obviously no Mac genius here. Hey, that's why I consult you guys/gals!

Also, random sleep seems to have stopped, maybe b/c I plugged G5 directly into wall.

However: gunning fan and rising temps:

When working in Photoshop, especially when performing high demand procedure, the fans pick up and the temp on CPU B increases to 200F plus (up from around 130F).
So it's up and down with the fan and CPU temp every time I make a move in Php.

Weigh in?

 

[Nameci]

I think that is normal, when the cpu does heavy lifting it would warm up and would cause the fans to cool it down, hence the higher rpm of the fans.

 

[MacHamster68]

photoshop like most other Apps cant use both processor cores at the same time, its only in the last 2 years when app makers think about to address the multi core use in their apps and try to make them use of all available cores .
but for the older apps , one core has to do the lifting , and it starts to sweat , the fans start cooling,
sounds normal to me too

I would anyway check for leaks very frequently in a liquid cooled PowerMac , the first sign is something that looks like white crystals building up between cpu and heat sink, the next is look for signs of green liquid and corrosion on the case .
If you see only the slightest sign and are in doubt if its necessary to address that little problem today : switch the PowerMac off immediately and overhaul the liquid cooling system , the liquid in the cooling system is highly corrosive, it will eat a aluminium case for breakfast , a PSU for lunch and a logicboard for dinner, so a leak can cause your PowerMac to die quickly