Power supply and fan replacements

> The fans in my Quad G5 seem to get faster and faster with each Leopard
> release. I've tried all the recommended methods, including pressing
> the SMU switch and resetting the PRAM but nothing helped.
>
> I've set the option in the energy control panel to "reduced". That
> seems to have helped a little but I hate to think that I'm not getting
> the maximum performance out of my computer.

Restart and hold down the CMD & S key to start at the UNIX prompt. Type fsck
-fy and if everything is OK, type exit. My G5 1.8 DP fans only get hyper
when there is a pending OS kernel panic or a piece of software freezes.
--
James Connolly

On Jun 10, 2008, at 6:04 PM, James Connolly
<james.connollysbcglobal.net> wrote:

> Restart and hold down the CMD & S key to start at the UNIX prompt.
> Type fsck -fy and if everything is OK, type exit. My G5 1.8 DP fans
> only get hyper when there is a pending OS kernel panic or a piece of
> software freezes.

That is unlikely to be any more helpful than a simple reboot.

Running fsck is useful if you have reason to suspect a hard drive
failure, but a failing hard drive isn't the most likely explsnation for
increasing fan noise, and if a drive is failing, you should also expect
to see one or more things like random hangs & app crashes, apps refusing
to launch or save, slower than usual boots, system freezes & kernel
panics, etc. He isn't describing anything like that.

There's not much harm in running fsck, of course -- its funtionally
equivalent to running Disk Utility from a boot DVD -- but it isn't
likely to help here.

I think the most likely remedies, roughly in order, will be:

  * clean out fans, ducts, heat sinks, etc
  * reinstall Leopard (archive & install)
  * get it checked out for possible hardware failure, including fans,
    CPU, logic board, or power supply, in about that order; just having
    them run the diagnostics and doing a thermal calibration may
    actually work without needing a hardware repair

(I did this sort of thing for a living until recently...)


--
Chris Devers
http://chrisdevers.vox.com

On 10-Jun-2008, at 11:23, Thomas Perrier wrote:
> Keep in mind that there isn't a secret formula to render computer fans
> silent: all you can do is decrease their rotational speed. There's
> only one
> way to reduce noise and simultaneously keep the same airflow:
> increase the
> fan's diameter, which allows it to turn more slowly while moving the
> same
> amount of air as the smaller fan spinning more rapidly. So
> basically, when
> you replace the original fan with one of the same size and which is
> more
> silent, that means it turns more slowly and that the generated
> airflow is
> lower, and that the computer is less efficiently cooled.


That's certainly not true. Reduced noise comes from a wide variety of
factors, including better bearings, tighter assembly, better motors,
and better design of the fan blades. And, yes, the size of the fan.
But to say that the size is the sole arbiter of noise is just wrong.

On Tue, Jun 10, 2008 at 3:04 PM, Chris Devers <cdeverspobox.com> wrote:
> I've seen it before if the machine is dirty inside.
> Have any pets?
>

Well, I do have eight cats.
I try to clean the inside as frequently as I can.


On Tue, Jun 10, 2008 at 3:04 PM, James Connolly
<james.connollysbcglobal.net> wrote:
> Restart and hold down the CMD & S key to start at the UNIX prompt. Type fsck
> -fy and if everything is OK, type exit. My G5 1.8 DP fans only get hyper
> when there is a pending OS kernel panic or a piece of software freezes.
>

I'd done part of it. All I did was to key "exit" after starting in
the safe mode. That's what one instruction that I found by searching
on the Internet said.

=====

Thank you, both, for your suggestions.

As long as I run the machine in "reduced" mode, the fans are fairly
quiet. But if I bump it up to Highest or even Automatic mode, they
almost immediately pick the speed. My room temperature, during the
summer, is in the low 80's . I know that has to do with the fan speed.
They are generally a lot more quiet during winter.


--
____________________
Ryoichi Morita

On 6/10/08 4:07 PM, "Ryoichi Morita" wrote:

> Has anyone else run into the same problem?
I'm on 10.4.10 not leopard.

Photoshop elements 4.0 quite noticeably raises the fan speed in my G5 quad.
The demo of PS 6.0 doesn't do it. And from time to time they simply rev
up to full blast - a simple restart fixes it. How many apps do you
typically run? Try and quit the ones that are un in use. Even PSE 4 loads
up fast enough for me to quit it every time I'm done using it.

When the machine was new (from the first boot) I needed to get new
processors due to unacceptable fan noise level. It took a week of
diagnostics at the shop where I bought it and another week to get the parts
but it was worth the wait.

Adam

On earlier G4 Power Macs, ATX power supplies CAN be used. No, they don't put out "different voltages" and I doubt "you'll be sorry" if you replace the expensive Mac supply with an ATX type of PC power supply. As an Apple Tech (who is no longer affiliated with Apple) I have done quite a few of these and you just need to make sure that the ATX-type PSU has the same or more output watts as the original. There are more than a few pinout diagrams to rewire the connector to work with the Mac. The best way, however, it to pickup an adapter that takes the guess work out of the whole thing. If you can fit the ATX supply in, then this guy makes the adapter for it. Just go here: <http://atxg4.com/order.html> Good luck and don't believe everything you hear. The internet is FULL of fairy tales. Sincerely, J. Wrobel