Why is my G5 drive bay fan speeding all the time

[SheerGold]

My G5 tower is one of the early models.

Today I turned it on. Immediately the drive bay fan was running at maximum speed. The Mac's temperature was cold as it had not been used for 12 hours. So the speeding fan could not have been due to the drive bay being overheated.

The fan never slows down.

Even after a restart it immediately spins at its maximum. Plus it stays at maximum speed all the time.

Anyone know what is causing this & how to make it work properly?

[lamina]

Shot in the dark here... turn it off, hold down the power button until you hear BOOOOOOOOOOOOOOOP and all the fans spin up to max, and release.

Also, hold down -Opt-P-R to reset PRAM.

Let us know.

[andy.barron]

Hi. I had the very same problem ages ago. Set the processor performance to best or fastest (sorry i'm not in front of my G5) instead of automatic.

I believe this will sort it for you:)