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View Full Version : PMG4 QS is dead! Help!!!




iLoveiMacs
Jul 16, 2010, 10:49 AM
I bought a Power Mac G4 Quick Silver (used) last April. It worked for about a month before it crapped out. The Specs are:

Dual 1.0 GHz PowerPC G4
1GB RAM
250GB HDD
M8667LL/A

When I boot it up by pressing the power button on the front of the computer, the light on the button turns on and i hear the fans start up for literally a second, and then it stops. I believe this might be the power supply. I would love to get this :apple: fixed! I would appreciate it if anyone could help me troubleshoot or better yet, help me find a power supply for the PM? I don't care how much it costs. Thanks for your help!



Kaji79
Jul 16, 2010, 01:44 PM
http://resale.headgap.com/g4powersupply/

This is a great site to diagnose if your psu is going out.

brassguy98
Jul 16, 2010, 08:12 PM
Sounds like a Logic Board to me

4JNA
Jul 16, 2010, 09:06 PM
Sounds like a Logic Board to me


i would disagree. the first thing i'd check is the PRAM Battery (http://eshop.macsales.com/item/Newer%20Technology/BAA36VPRAM/) as i've seen it cause this exact symptom. pull the old one and check it with a multimeter, or take it into a store to have it checked, or just replace it because they all need replaced at this point...

second would be the power supply. possible to rig a cheap/standard ATX supply, but for the non-modder, i'd stick with an actual OEM replacement. best of luck.

666sheep
Jul 17, 2010, 02:18 AM
Sounds like a Logic Board to me

Probably, symptoms are similar.
But it's quite easy to ensure that it isn't PSU.
OP, check PSU this way: http://www.instructables.com/id/How-to-power-up-an-ATX-Power-Supply-without-a-PC/
See which pins you got to short: http://www.outofspec.com/frankenmac/wire.shtml
If PSU will start, your logic board is dead.
PRAM battery has nothing to do with those symptoms - almost every Mac will start and run without this battery.

4JNA
Jul 17, 2010, 01:53 PM
...PRAM battery has nothing to do with those symptoms - almost every Mac will start and run without this battery.

i disagree, as i've worked on lots of systems with the same symptom and were all related to a dead PRAM battery.

i agree that the machine will normally start and run just fine without the battery, as i have a pismo that i uplugged the battery in years ago and it works just fine.

the thing is, that when the battery goes dead, if PRAM/CUDA get corrupted, the machine will no longer turn on, and the battery has no power to reset CUDA when the button is pushed (ONLY ONCE!)

i'll stick with - replace PRAM battery, reset CUDA (http://docs.info.apple.com/article.html?artnum=95065) (yes, i know it's for a different machine, it works the same for all) and then hopefully boot and reset PRAM (http://support.apple.com/kb/ht1379). best of luck.

666sheep
Jul 17, 2010, 04:54 PM
I've never had such an issue caused by dead battery (about 100 QS and MDDs passed through my hands) but cannot negate that you had ;)
Let's see what'll be OP's experience in this case.

iLoveiMacs
Jul 17, 2010, 07:25 PM
Thanks for the replies! I'm on vacation right now but I'll try all of your suggestions tomorrow and see what I come up with. I'll be sure to let you all know!

4JNA
Jul 17, 2010, 09:07 PM
I've never had such an issue caused by dead battery (about 100 QS and MDDs passed through my hands) but cannot negate that you had ;)
Let's see what'll be OP's experience in this case.

i agree. nothing against your post/recommendations, just have seen lots of systems over lots of years, and if i'm wrong, so be it. it won't be the first time...

...I'll try all of your suggestions tomorrow and see what I come up with. I'll be sure to let you all know!

hope you can get it fixed. the QS is still one of my favorite systems of all time. crazy/awesome/beautiful case! best of luck.

iLoveiMacs
Jul 18, 2010, 04:47 PM
I came home today and tried the CUDA switch, but it didn't work. I'm convinced that the Power Mac needs a power supply. Can anyone recommend power supplies/places to get them through this thread or by PM? Possibly links? I don't even know what to "Google" or search on eBay. :confused:

666sheep
Jul 19, 2010, 03:14 AM
If you're sure it's PSU, you need this: http://www.welovemacs.com/6612513r1.html - but price...:eek:
Did you test PSU like I've suggested? It's easy: you need a little thick wire, short out PW OK pin (green wire) with GND (black wire) then connect power cord to PSU. Connect HDD to one of molex plugs, to give PSU some load. If it will start this way - it's OK.
If not - search eBay for proper PSU. If you are not using ADC connector on your graphics card, you can mod ATX PSU to work in your QS. Use pinouts from site I linked. This will be helpful too: http://atxg4.com/quicksilver.html