MDD g4 will boot from start button into os 9, but not osx

Question

MDD g4 will boot from start button into os 9, but not osx

Hi-

I have a MDD G4 that will boot from the start button into OS9, but not into OSX. In order to start from the start button I have to unplug and then replug the unit.

It powers down from the menu fine. It restarts from the menu fine.

What I've done:

Replaced the PMU battery

Zapped the PRAM

Zapped the PMU

Left it unplugged wthout a battery for over an hour and then replugged the unit and the battery back in. Powers up, but not after a new shutdown.

As long as I leave it on, it works fine. Even sleeps fine.

Anybody have any ideas? PSU?

PowerMac, Mac OS X (10.4.11)

Posted on Dec 19, 2011 11:47 PM

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Answer 1

BDAqua

Level 10

238,997 points

Dec 20, 2011 12:25 AM in response to Minneota Madman

Hello, some things to try...

Hold the x key at bootup/power on.

Hold the Option/alt key at bootp to see boot choices.

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Answer 2

Dec 20, 2011 6:29 AM in response to Minneota Madman

With the Mac up & running, check the OS selection in the Startup Disk preference window. Make sure it's OS X.

 Cheers, Tom 😉

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Answer 3

Dec 20, 2011 12:42 PM in response to Texas Mac Man

I think perhaps I have been unclear.

When the start-up disk is set to osx, and I press the power-up button in the front, nothing happens. No light, no fan etc. If I unplug the unit and then plug it back in, then it will start-up.

If the start-up disk is set to OS9 and I press the power-up button, it starts without any problems.

Other than this start-up gremlin, the unit works fine.

However, I fear for the future of my machine and data.

R.

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Answer 4

BDAqua

Level 10

238,997 points

Dec 20, 2011 1:05 PM in response to Minneota Madman

What happens if it's set to startup OS9, but you hold the Option/alt key on powerup & choose OSX to boot from there?

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Answer 5

Dec 20, 2011 2:39 PM in response to Minneota Madman

If it was a power supply problem, it wouldn't boot to OS 9.

Do you have a backup hard drive that's bootable? If so, set the Startup Disk preference to boot OS X from the backup & see what happens.

 Cheers, Tom 😉

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Answer 6

Dec 20, 2011 3:29 PM in response to Texas Mac Man

That's the weirdness... I do have multiple bootable disks and it won't start-up from the button into 10.2, 10.2.8 or 10.4.11. But it will boot into os 9.2. I'm wondering if there is a different initial command set for os x and os 9 when you push the button.

R.

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