Dumpster iMac

[Niode]

As a life long mac user, take my advice and stay away from anything non-intel. We had a G4 iMac and when we updated OS X, almost none of the applications would run. If you want to have a mac as a primary computer, you NEED an intel processor. Motorola processors were great in their day, but almost no one continues to support them.

I can verify that the G5 iMacs are perfectly fine running OS X up to leopard (we never upgraded them to snow leopard at College since Pro Tools 8 had issues with it at first) they ran all the programs we needed them to run (Office, Pro Tools 8, Logic Studio 8 ). Trust me, I had to install them all one by one and make sure that they were 100% stable before we let the students on them.

[samsonlonghair]

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[Hobie-wan]

Just because the trickle voltage is working doesn't mean that the other power channels used when running are working. Check the board for any burns or popped capacitors. If possible, borrow another power supply from a working G5 and try.

So just because the LEDs indicate a trickle voltage, I can't rule out power supply failure. Thanks. That's vital information. I didn't see any burnt caps on the motherboard, but I can check again. I don't know if I can find another G5 power supply laying around, but I'll spend a few days looking. If I can prove that the only thing wrong with this iMac is the power supply, I'll gladly replace that and have a working mac.

Yup, on a PC there's standby voltage, which is probably equivalent to the trickle one, then there's separate voltage rails for the mobo/processor, 5 volt, and 12 volt as needed for the various components. One of my old PCs had a similar problem for a while that if I turned it on, the PS would make a popping noise. I had to unplug the PC for a few seconds, then it would usually start up. So hopefully it is just PS. If you know anyone with a G5 that will let you test with their PS for a few minutes, it will help determine if the problem is there. If you don't see any damage otherwise in the PC and don't see anything shorting anywhere (check for paperclips behind the motherboard) then you probably don't have to worry that the system had killed the power supply.

[samsonlonghair]

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[Niode]

The G5 imacs are pretty good machines. Which model is it? Is it the one with the isight camera in it? Those are the ones we have in one of the rooms at the college. The iSight models are the latest version of the iMac line pre-intel. We are music college so the adobe software suite is something I'm not familiar with at all.

[CRTGAMER]

Electrical tester will confirm power outs on that supply.

I've got a cheap-o multimeter that I use just to keep myself from getting electrocuted if I have to fix an outlet or something. Is there a way I can I use this to test the caps on the motherboard?

Thats all you need and be careful. Be sure to set for correct voltage range. Just use it on the power supply.

Pinout voltages Could not find G5 pinout.
Careful, this pinout is for the G4 unsure how G5 is different:
http://docs.info.apple.com/article.html?artnum=95064

Found this for you:
http://manuals.info.apple.com/en/imacg5_17inch_power_supply.pdf
http://support.apple.com/kb/HT2173

A PC ATX Power Supply to fit G5 Tower mod:
http://damntechnology.blogspot.com/2009/02/rebuilding-powermac-g5-power-supply.html

I used your Video Term you hate, sorry.
http://www.racketboy.com/forum/viewtopic.php?p=228873#p228873

[CRTGAMER]

More PDF's that might help.

http://www.jimwarholic.com/docs/Apple-iMac-G5-Power-Supply.pdf

http://jimwarholic.com/docs/Repairing-Apple-iMac-G5-Motherboard.pdf

[obi-shawn]

Really? Leopard? I've never gotten a PowerPC to run anything better than Tiger. Is there a trick to it? Do I need a firmware update for this model? Since you have experience installing software on G5 iMacs, what is the newest version of Adobe creative suite you think will run on this hardware?

Leopard should run fine on a G4 or G5 mac as long as it meets the system requirements. I've installed it on a lower system before, but the install required some tweaking. It was a dual 800mhz G4 though, so it still ran pretty well.

Most of the mac programs still out there are universal binaries, so they'll work on a powerpc and intel mac. As programs get updated for Snow Leopard though I can see that going away as Snow Leopard is the first OS that requires an Intel chip.

Adobe CS4 will still work with PowerPC Macs as long as it has a G5 processor. Again here are the system requirements.

Your issue does indeed sound like the power supply. I hope you're able to find one to test with and get it up and going. A G5 is still a very good machine. I work at a college campus and our Design Center still has a few G5 Power Macs in use and a lab with G5 iMacs.

[CRTGAMER]

Really? Leopard? I've never gotten a PowerPC to run anything better than Tiger. Is there a trick to it? Do I need a firmware update for this model? Since you have experience installing software on G5 iMacs, what is the newest version of Adobe creative suite you think will run on this hardware?

Leopard should run fine on a G4 or G5 mac as long as it meets the system requirements. I've installed it on a lower system before, but the install required some tweaking. It was a dual 800mhz G4 though, so it still ran pretty well.

Most of the mac programs still out there are universal binaries, so they'll work on a powerpc and intel mac. As programs get updated for Snow Leopard though I can see that going away as Snow Leopard is the first OS that requires an Intel chip.

Adobe CS4 will still work with PowerPC Macs as long as it has a G5 processor. Again here are the system requirements.

Your issue does indeed sound like the power supply. I hope you're able to find one to test with and get it up and going. A G5 is still a very good machine. I work at a college campus and our Design Center still has a few G5 Power Macs in use and a lab with G5 iMacs.

obi-shawn, Great info!

Just be careful which version Leopard Install disc:

http://en.wikipedia.org/wiki/Mac_OS_X_Leopard#System_requirements

Leopard’s retail version was not released in separate versions for each type of processor, but instead consisted of one universal release that could run on both PowerPC and Intel processors. Leopard drops official support for slower G4 and all G3 processors.

Because all new Macs use Intel processors, the versions of Leopard shipped with them are Intel only.

[samsonlonghair]

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