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My powermac g4 starts up and shuts down immediately after. Why?

I have a Powermac G4 (PowerPC 7455) dual 1.42 GHz, 2x120 GB hard disks, 2x150 GB hard disks, 4x500 GB Ram

I erased all disk and started to install Leopard on one of the 120 GB disk and, during the installation it freezed.

I had to force shutdown and since then it's been impossible to try the Mac Osx install again. Everytime I push the start up button, 1 second after the startup sound it shuts down. Can anyone help me.

Posted on Apr 5, 2015 1:38 PM

Reply
21 replies

Apr 13, 2015 6:24 PM in response to BDAqua

Didn't work either...
I'm buying a new PRAM/Motherboard battery tomorrow and check if it works like that.
If not I'll just have to admit I don't know what's happening and take it to a Apple support store. 😟
We put to practice all the possible scenarios on this. Maybe it's one of those "right in front of our eyes" thing.
Anyways. If I find anything new about it I'll post here for community sake.


Thanks again for all your help BDAqua!

Apr 16, 2015 5:01 PM in response to BDAqua

So. I have news.
This tech guy borrowed me an external drive with a bootable Leopard OS which I connected to the G4 and it was immediately recognized when I powered it up pressing the Alt key.


I managed to install Mac OSX 10.5.8 and finished installing all the software I needed and that I still had from back then.

I restarted it and transferred the files with a bi-directional ethernet cable from the iMac to the G4. I finished the job and shut it down.

Later that night I started it up again and that grey screen with the chinese/japanese/whatever characters appeared.

I called my tech friend and he told me it might be one (or more) defective RAM modules.

So. I'm going to try to find some PC2700 DDR 512GB RAM modules and buy them.


Not finished yet!

See you soon.

May 8, 2015 6:16 PM in response to BDAqua

So... My RAM sticks are fully functional. I Just bought the 3.6 volt lithium motherboard battery! I've spent more than a month looking for the bloody thing. Everyone I asked about it gave me "that look"... It seems that no one knows what a motherboard battery is and the ones who know always thought that they would look like a watch battery... I know. This was a kind of reality check. I'm 45, looking for a battery for a 15 year old Mac... why the ****... keep it simple idiot!

I guess this is a worse situation than our parents changing from a typewriter to a 286 processor...
I bought the battery, Put it on its rightful place on the motherboard. It started it like a "real Mac". I restarted it 3, 4, 5 times and I thought... That's it! I made it. It's working. Shot it down and left home for about 4 hours and the first thing I did when I arrived home was to click on the start up button... no-thing.. I'm so ******! What the **** is happening here!?

Apr 6, 2015 10:21 AM in response to nunotuna

Hi, I don't know how fast it shuts down, but...


How to reset the SMU/PMU on a Power Mac earlier G3, G4, G5 models...


http://support.apple.com/kb/HT1939


Have you done a PRAM reset, CMD+Option+p+r...


http://support.apple.com/kb/ht1379


In fact, do 3 in a row, takes a bit of time.


Does it boot into Open Firmware with CMD+Option+o+f ?


http://docs.info.apple.com/article.html?artnum=42642


reset-nvram (press Enter)

set-defaults (press Enter)

reset-all (press Enter)

Apr 6, 2015 10:35 AM in response to BDAqua

Hi BDAqua.

Thanks for the quick reply. I did try to reset the PRAM with no results whatsoever. I installed Leopard remotely from my imac last night having the G4 as target disk and it continues not recognizing the assigned system disk. I guess it's because the installation adapted to the host iMac parameters and not to the G4's.

I will try all those commands you're suggesting tonight and get back to you.


Thanks again!

Apr 6, 2015 12:35 PM in response to BDAqua

This what I've tried:

iMac 2.66 Intel Core 2 Duo ----> Mac OSX Leopard 10.5 Install DVD ---> PPC G4 (target mode)

I successfully installed it but when I tried to turn the G4 it fired up and shut down immediately after. Now it just lights up the start up button and has no reaction whatsoever. Like when you start up a car and it has no battery.


I've been working with Macs since early nineties and I got used to solve my own software and hardware problems but I'm getting desperate with this one because I've tried all the "tricks" I know unsuccessfuly.

My powermac g4 starts up and shuts down immediately after. Why?

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