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Mac won't start up...

M

mamlukman

macrumors member
Original poster
Nov 5, 2013
41
1
I went on a short vacation and so I unplugged all my computers, the modem, and the phone line to the modem.

My backup computer is a G4 Mirrored Door Drive. I've never had any issues with it. But this time it won't start up: It gives a 2-second "whirrrrr....." and then nothing.

I fear the worst, but any thoughts?
 
M

mamlukman

macrumors member
Original poster
Nov 5, 2013
41
1
macuser453787 said:
It might be that the PRAM battery needs to be replaced. A similar thing happened to me many years ago with my G4 Digital Audio.

You can try replacing it with a 3.6V lithium PRAM battery like this one and see if that works.

Incidentally, your question is a topic for the PowerPC Macs forum instead of the Mac Pro forum. :)
Click to expand...
macuser453787 said:
It might be that the PRAM battery needs to be replaced. A similar thing happened to me many years ago with my G4 Digital Audio.

You can try replacing it with a 3.6V lithium PRAM battery like this one and see if that works.

Incidentally, your question is a topic for the PowerPC Macs forum instead of the Mac Pro forum. :)
Click to expand...

Good idea. It's been so long that I've changed the battery I didn't even think of it. I've ordered one. Hope it works.

As for the forum, the only choices I saw were "mac Mini" "Mac Pro" and something else...but NOT Power PC. Maybe they're got categories in several places. I've always found this forum hard to use!
 
AphoticD

AphoticD

macrumors 68020
Feb 17, 2017
2,283
3,466
Roman78 said:
Once... a long time ago... i converted a normal ATX power supply into the MDD. Modified it so that it even fits into the original power supply cage.
Click to expand...

There are pin out diagrams and instructions for using an ATX PSU in the G4s at http://atxg4.com/

Given a bit of patience, it should be easy enough to adapt. Just be aware that the GPU will no longer be able to power the ADC port for an Apple Cinema Display.
 
M

macuser453787

macrumors 6502a
May 19, 2012
578
151
Galatians 3:13-14
Roman78 said:
The MDD should start with the battery removed.
Click to expand...

When a similar issue happened with my DA G4, it wouldn't power up until I replaced the PRAM battery. Before I did that, the power light on the front would fluctuate on and off and the fan would run, but no power up.

Roman78 said:
It could be the power supply.
Click to expand...

Possibly. I suggested the PRAM battery because the OP mentioned unplugging the computer for a while, which could have caused a drain on the PRAM battery especially since it had been so long since it was replaced.

AphoticD said:
There are pin out diagrams and instructions for using an ATX PSU in the G4s at http://atxg4.com/
Click to expand...

Some years back I found that website, looking for a way to use a standard ATX power supply with my DA G4. This guy wasn't making the adapters at the time, but when I asked him he made one for me. He was really nice about it and the product worked perfectly. :)
 
M

mamlukman

macrumors member
Original poster
Nov 5, 2013
41
1
I replaced the PRAM battery with a new one--no difference. The power button lights up for a fraction of a second, then goes dark. Also a fraction of a second of noise from inside. I guess the next step is the power supply. I do have an identical (?) MDD G4 that I kept for "parts" and I will take the power supply from that and see what happens.

And yes, if I have an issue, I do post it on a couple different web sites--it's not that I don't "trust" one over the other, I simply assume different people might look at different ones!
 
M

mamlukman

macrumors member
Original poster
Nov 5, 2013
41
1
OK, it's working--I had already replace the PRAM battery, bushed the PMU button, etc. with no change. Luckily I had a duplicate G4 just in case I found myself in this situation. After watching a couple Youtube videos, I tested the "spare" computer. It started up. So I removed the power supply and put it into the "good" computer. Now it works fine. So it was the power supply.

I'll add a suggestion to those who make videos: it took me two days and probably 6-7 hours to do this, and Ive drew blood about 4-5 places. Why? Because the videos assume you know stuff--and if I knew stuff, I wouldn't have to watch the video!!! Like what? Well, screws are pretty obvious. Getting to them is another matter. Then there are always some sort of hooks/brackets on the back of all the cages, power supply, etc. etc. Which way to they go? Do you push up, left, right, or down to release them from the hooks/brackets? On on the drive cages there is a white lever you have to push to release them. None of the videos dealt with any of this, so it took me forever with trial and error. Yes, if you replace power supplies or drives every day it's "obvious," but someone like me who deals with this sort of thing every 5-6 years is clueless. PLEASE--if you make a video, make it for people like me!


mamlukman said:
I replaced the PRAM battery with a new one--no difference. The power button lights up for a fraction of a second, then goes dark. Also a fraction of a second of noise from inside. I guess the next step is the power supply. I do have an identical (?) MDD G4 that I kept for "parts" and I will take the power supply from that and see what happens.

And yes, if I have an issue, I do post it on a couple different web sites--it's not that I don't "trust" one over the other, I simply assume different people might look at different ones!
Click to expand...
.
 
eyoungren

eyoungren

macrumors Penryn
Aug 31, 2011
29,603
28,365
mamlukman said:
OK, it's working--I had already replace the PRAM battery, bushed the PMU button, etc. with no change. Luckily I had a duplicate G4 just in case I found myself in this situation. After watching a couple Youtube videos, I tested the "spare" computer. It started up. So I removed the power supply and put it into the "good" computer. Now it works fine. So it was the power supply.

I'll add a suggestion to those who make videos: it took me two days and probably 6-7 hours to do this, and Ive drew blood about 4-5 places. Why? Because the videos assume you know stuff--and if I knew stuff, I wouldn't have to watch the video!!! Like what? Well, screws are pretty obvious. Getting to them is another matter. Then there are always some sort of hooks/brackets on the back of all the cages, power supply, etc. etc. Which way to they go? Do you push up, left, right, or down to release them from the hooks/brackets? On on the drive cages there is a white lever you have to push to release them. None of the videos dealt with any of this, so it took me forever with trial and error. Yes, if you replace power supplies or drives every day it's "obvious," but someone like me who deals with this sort of thing every 5-6 years is clueless. PLEASE--if you make a video, make it for people like me!



.
Click to expand...
Videos are not always the best thing. I've had to use one from time to time, but it's never my first resort.

I usually go here: ifixit.com

In your case, with your Mac, this was a covered guide: https://www.ifixit.com/Guide/Power+Mac+G4+MDD+Power+Supply+Replacement/1622
 
1042686

1042686

Cancelled
Sep 3, 2016
1,575
2,326
My acbel psu on my dual 2ghz pmg5 failed & had to be replaced. I did take the time to scavenge the fans & some other random bits off it though. Glad you got yours fixed :)
 
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