PPC G5 Dual 2 on all the time

mediaman67

Registered
Hi All,

New here, thought I'd ask this, and see if anyone has a clue...

G5 DP 2.0, PPC, with 3.5gigs RAM Running Tiger (last/latest 10.4.11)

Here's the deal...

If I try to boot the machine, or restart the machine, it will start to boot, and then shut off right away...

the only way I can get this to boot, is to hold down the cuda button for 5+ sec, and then if I reboot it's fine...

this is repeatable now - happens like every single time - the workaround for me has been to just leave the machine on 24/7, which is fine, since I do almost use it that much at times, but it's still not the way it is supposed to work, of course.

do I have a Dead battery? what would cause the need to do a reset like that EVERY time from either a cold boot, or a restart?

Once it boots, it will run forever... and rarely ever freezes too, which is nice, but would like to get to the bottom of it, and if it's something as easy as a battery, that would be good news.

Thanks all
 
the only way I can get this to boot, is to hold down the cuda button for 5+ sec, and then if I reboot it's fine...

Not sure what you mean by "cuda" button. But anyway, Id start by running disk utility verify on the boot drive to see if any errors come up. Post back with results.
 
it's a button on the motherboard that does a hard reset to the PRAM basically - has been on PPC macs since the Blue and White G3... very common thing to do when all else fails...

the power outage is way before the drive even gets read - it's something in the boot sequence that happens early...

Google cuda switch for G5 and you will see apple docs on it, etc...

Thanks
 
Okay the SMU reset button. Never in all these years as a tech heard it called a cuda button. I would check the drive on the machine, especially if you can get the machine to boot to a disk or another drive every time. If it shuts down no matter what it is booting from then it might be the PSU.
 
ok, well, before it was called the SMU reset button, it was known as the Cuda - google it, and you will see that I'm not making it up, it's an Apple Term - but for the G5, I think they did do away with that tech, and call it SMU now, so we are both right.

so, you are saying, to pick another start up disc, and try that, and if it boots, it's the drive, and if it doesn't, it's the PSU? it pretty much chimes, and 5 sec later shuts off...

how much are they to replace? are they part of the Logic Board, or what? as I said, it boots fine after the SMU is reset, without fail... but has to be done everytime you are restarting or booting from start up.

I am using tiger mostly, but can also boot into Leopard as well... Tiger seems snapper for my needs, but I have the choice, since some software I have requires Leopard.
 
so, you are saying, to pick another start up disc, and try that, and if it boots, it's the drive, and if it doesn't, it's the PSU? it pretty much chimes, and 5 sec later shuts off...

Yeah, thats kind of what I'm saying. But like I said you really need to try to boot to a install disk or a completely different drive altogether to have more to go on. Do you have the Tiger or Leopard installers. If you do try to boot to them. If it boots to disk successfully go to utilites/disk utility and try to repair the disk from disk utility to see if it will successfully repair or give errors. It might not even be a bad drive but just a really screwed up directory structure on the drive.
 
I have 4 separate drives in that machine, so yeah, the os is on a whole other drive, and I have both Tiger and Leopard original discs, Tiger is handy - that is a good test though, I'll try that...

So, what if it is the PSU? does that mean the Logic Board is hosed, or what is the repair?

Thanks
 
So, what if it is the PSU? does that mean the Logic Board is hosed, or what is the repair?

Just means it needs a power supply unit a.k.a PSU. The PSU is not a part of the logic board. But if it gets to the point where you are sure its not the drive causing it, you might want to get an authorized Apple shop to look at it to make sure the processor(s) and logic board are okay also. I'm a tech and I've looked at several machines like yours so my opinion is pretty valid. But I'm not going to tell somebody to buy something to fix their machine on a help forum without seeing it, especially since those G5 towers aren't the easiest machines to troubleshoot.
 
oh yeah - PSU - DOH! - I always just think of these as a Power Supply...

Yeah, it would be interesting to find out... maybe I'll just try to find a parts machine on Ebay, and swap Power Supplies and see if that fixes it, which is something I had thought of too... but my guess is that it's something that is a miss with the Logic Board, since if it was the power supply, I would think it couldn't power the unit on at all, but who knows...

My other G5 had a similar problem that Apple fixed under the Apple Care warranty - that one was the Logic Board, and it would not power on at all, and not even try...

My 3rd machine is a G5 1.8, single processor, and it has the least amount of issues! - I hope that Apple's intel machines are more solid than the dual PPC machines in the G5 line... great when they work... even though the newer machines are a lot faster of course.
 
Just make sure you try to boot to a disk or another drive before assuming its something else. A bad hard drive or corrupt directory structure on a drive will display those symptoms and the best way to check is by trying to boot to another drive or bootable CD/DVD.
 
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