How to reset PMU in Digital Audio G4?

Question

How to reset PMU in Digital Audio G4?

Are there any procedures required other than powering down, disconnecting all leads, opening the case and pressing the PMU button (located on mobo with "S1" marked next to it ) ??

I can not find any tech articles on resetting the PMU on a Digital Audio G4 Power Mac despite doing numerous searches.

Thanks

Posted on Aug 24, 2006 5:23 PM

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Answer 1

WWJD

Level 6

15,830 points

Aug 24, 2006 5:56 PM in response to Murray Campbell

Here is where a link used to be regarding the reset:

PMU <Diagram> Switch for Some PM G4s:
http://docs.info.apple.com/article.html?artnum=95035

PMU Procedure:
http://docs.info.apple.com/article.html?artnum=95037

Regards,

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Answer 2

Aug 24, 2006 6:43 PM in response to WWJD

Thanks.

Someone has suggested to me to try resetting the mother board as opposed to the PMU (which I have done and it hasn't resolved my problem.

Any articles on that would be greatly appreciated. Its a Digital Audio G4.

cheers

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Answer 3

WWJD

Level 6

15,830 points

Aug 24, 2006 6:48 PM in response to Murray Campbell

Here's one other article but not overly useful:

http://docs.info.apple.com/article.html?artnum=58418

Looks like the DA model was just before my Quicksilver. What is your problem? Machine will not start?

Regards,

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Answer 4

Aug 24, 2006 6:59 PM in response to WWJD

What is your problem? Machine will not
start?

Regards,

It will no longer boot from either a partition with 9.2.2 or from a bootable CD with 9.2.2 on it.
It boots ok from 10.4.7 partition and from OSX Tiger DVD.

If I boot up holding the option key I can see the 9.2.2 partition/disc as a start up option but if I select either I do not get past a grey screen.

In startup disc preferences anything with 9.2.2 on it (partition or disc) shows up as a restart option but will not go past gery screen

Classic still runs from the 9.2.2 partition....

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Answer 5

WWJD

Level 6

15,830 points

Aug 24, 2006 7:01 PM in response to Murray Campbell

I really hesitate mentioning repairing permissions but I've read of more wild things have been solved from this process. I, unfortunately, am not an expert with OS9. You might check in the OS9 forum with your problem. It does not sound like a PMU issue. When booted from OS X, is the 9 partition visible from System Preferences > Startup Disk?

Regards & Good Luck!

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Answer 6

Aug 24, 2006 7:50 PM in response to Murray Campbell

Hello! Here is the da pmu location.

[IMG] http://img142.imageshack.us/img142/9686/qsdalogicbd8aa.jpg[/IMG]

Sometimes the disk that has the os9 OS on it becomes corrupted and while classic will work a machine won't boot from it. I've at what you're describing happen and while DiskWarrior might fix it I had to resort to a clean install of OS9 to get it booting again. Tom

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Answer 7

Aug 24, 2006 8:00 PM in response to WWJD

When booted from OS X, is the 9 partition
visible from System Preferences > Startup Disk?

Regards & Good Luck!

Yes, as stated in the post you replied to but thanks for the thought.

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Answer 8

Aug 24, 2006 8:03 PM in response to Thomas Bryant

Hello! > Sometimes the disk that has the os9 OS on it becomes
corrupted and while classic will work a machine won't
boot from it. I've at what you're describing happen
and while DiskWarrior might fix it I had to resort to
a clean install of OS9 to get it booting again. Tom

Thanks Tom but I have a bootable CD with 9.2.2 on it which has worked for the past 2 years and there is no way that could become corrupted but although startup disc prefences in 10.4.7 recognizes this disc as start up option it will not boot beyond a grey screen.......

cheers

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Answer 9

Jon Smith

Level 4

1,390 points

Aug 24, 2006 8:18 PM in response to Thomas Bryant

Hello Murray and Thomas,

On my dual HD, dual boot DA, I had a similar problem following an unsuccessful attempt to install a flashed PC Geforce 3 video card.

Wouldn't boot in OSX at all, would boot in OS9 only if I unplugged the OSX(10.3) HD and set the startup disk from the OS9 install CD.

Reset the pmu, no help; repaired permissions, no help; ran disk first aid - DFA said fine; ran Disk Warrior - DW said fine; I could see all drives - I just couldn't boot. All I got was the Apple prohibitory sign - the "No Parking" sign.

Solution was tu reinstall OSX. Install went smoothly and have had no problems since.

HTH ..... Jon

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Answer 10

Aug 24, 2006 8:27 PM in response to Jon Smith

Thats interesting Jon.

Of course I have no problems booting from my OSX drive or from the Tiger DVD......food for thought though.

thanks

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