PowerMac G5 Dual 2GHz freezes any time, boots sometimes with one processor

Hi Tenoch T,

I have something Drew referred to if you'd like to email me here: No5MkI@gmail.com

I don't know about a conspiracy but three years does seem to be about the time when people start running into trouble with their G5s. Really I think G5s run too hot by nature and that might be the reason why so many fail. My bitter experiences have convinced me to keep mine, "cool and clean".

I've heard good things about this company should you reach the point of wanting repairs. Unlike Apple, they actually repair and not just replace: http://www.dttservice.com/appledesktops/powermacg5.html

Drew,

I think it would be good to call Applecare and convey something nicely like this, "Look, I'm 3 months out from Applecare and I have serious problems...".

One never knows what could happen.

I'll try running those AHT.
About the dirty PSU, that's the picture I wrote about.
I used that website yesterday as a guide to get to the heatsinks units, everything went well so today I'm gonna continue and clean the PSU.

I called my local Apple Store when the problem started and since my AppleCare had already expired they told me that I had to pay for labor and parts so that's why I decided to check out my self and see what i can find.

This is the only site I found regarding Apple doing something about G5s
http://www.apple.com/support/exchange_repair/powermac.html

But my G5 doesn't fall into the range of Serial numbers that they pointed out.

Thanks for that link, Drew. That's a good page and I made a print of it for future reference. I bet the person who had that machine was a smoker. The dust in my first G5 had that color tinge and I'm one. I'm taking great pains to isolate my tower as much as possible from it's effects. Seems I care more about my mac than I do myself. Take that, Steve Jobs.

This is almost word for word the problem I'm having right now.

Sounds like a pretty chronic issue with DP G5s. I haven't seen anyone offer a fix up yet. Guess I'll take it into the shop. Have a bad feeling it's the logic board.

Sorry for being dumb, but which reply are you replying too WorldChampRecordings ?
I personally think that Tenoch T's issue may not be the same, or if it is his seems more advanced. My G5 will start up with either 2 processors (when cool) or one after being used a little.

Just out of interest what is you spec of the G5 WCR?

Mine is dual 2.3Ghz (Early 2005) serial begins CK532

Tenoch T, if you got the handy PDF from Samsara have you considered removing the logic board too?

I reseated both processors and it made no difference, I also de-fluffed the PSU. It was dusty, but not particularly bad. Take a look at the state of the resistors below - all of the heat shrink has peeled up. I wonder how this could cause one processor to not show up. - I'm awaiting the Hardware Monitor licence to be able to see the voltages & get more temp readings. I was wondering if the proccessors get independent voltage feeds from the PSU - does anyone know? (Time for more service sauce I guess 🙂 )

http://pixelchimp.net/g5-psu/20081016_20413.JPG
http://pixelchimp.net/g5-psu/20081016_20401.JPG
http://pixelchimp.net/g5-psu/20081016_20402.JPG
http://pixelchimp.net/g5-psu/20081016_20411.JPG
http://pixelchimp.net/g5-psu/20081016_20412.JPG

After I reassembled it it was quite depressing to see the same thing happen again. The only other thing I can think of is removing the logic board to look for any dirt or damaged solder joints on the rear.

PS I'm in the UK (I modified my profile today) so I would try these guys for a processor or two http://www.applemacparts.co.uk/store/ but that is too expensive for me to consider at the moment, but a PSU may be affordable. It was where I got a replacement PSU for my dual 450 G4 when it failed!

Message was edited by: Drew Reece
[edit: corrected links]

Message was edited by: Drew Reece (Re:co)

Oh, I was replying to the post about having the computer freeze, then the "jet-fans".... then no start-up, followed by almost identical symptoms to mine. I run a dual 1.8 G5 with 2 GB Ram.

The quick description of my problem... .

1. Computer froze on the display-saver.... fans were blaring.
2. Forced down, thinking I'd just re-start only to find that it started to black... then a series of freezes.
Wouldn't allow me to reinstall. Even freezes in target mode!

Removed the hard drive, brand new one... same problem. Starts up for a few minutes, but even from the CD-boot... freezes cold and needs to be forced down.

It's absolutely a hardware or firmware issue, but I have no idea which. It won't stay "unfrozen" long enough to even run a hardware test.

(It was Techno T's post that seemed to mirror my experience and many others.)

Hey Drew,

Parts aren't that much cheaper here but they are less than that store you've dealt with. Doubt it would be worth getting one from the States but here's a look at what they're going for at one place: http://www.dvwarehouse.com/Power-Mac-G5-Logic-Boards-c-253238_2451074.html
Check out the price for PSs while your there too.

Those pictures are something, I'm surprised you didn't smell smoke. In case I missed it, your PS doesn't fit into this category does it? http://www.apple.com/support/powermac/powersupply/repairextension/

I use Hardware monitor also. The license number comes pretty quick. It's a good app.

Hey Drew!
Today I dissembled my G5, took out the 2 heatsinks, the logic board and finally the PSU. The PSU was dusty! I've clean all the parts using a brush, a vacuum and a compressed air can.

-"After I reassembled it it was quite depressing to see the same thing happen again."-
I'm sure this is what will happen to me too.
I was going to put everything back, since I've only removed the dust, I'll follow your steps and look for cold solder joints, or unusual things on the PSU, those resistors on your PSU are trippy.

Here are some pics of my G5
http://farm4.static.flickr.com/3063/2950233053_181b362ff5.jpg?v=0
http://farm4.static.flickr.com/3218/2951086192_bd885c641e.jpg?v=0
http://farm4.static.flickr.com/3015/2950233733_a59a406878.jpg?v=0
http://farm4.static.flickr.com/3192/2950234099_40a655595b.jpg?v=0
http://farm4.static.flickr.com/3251/2951087202_a63282e131.jpg?v=0
http://farm4.static.flickr.com/3004/2950236347_16e748b4d6.jpg?v=0
http://farm4.static.flickr.com/3195/295023681503d54c41ddo.jpg

I'm still on the mist, I don't know where the source of my problem is coming from;

1. Logic Board?
2. Heatsink?
3. PSU?
4. A combination of the any of the three?

I wish I had a spare G5 to swap parts and try to isolate the source of the problem without actually buying the parts 1st.
Oh well, time to continue.

Here's a message I got while trying to reinstall OS Tiger, a few weeks ago.
http://img369.imageshack.us/img369/8193/dsc0374ws7.jpg

Tenoch T, do you have a voltmeter to test the PSU (and an understanding of how to use one)?
There are some tests outlined in the Service Source manual. I really can't think of anything else to do without switching out parts with known good ones.

I haven't smelled any burning from my G5, note the scorching on the PSU board too, it doesn't seem right.


I think there are several stages to this issue, I'm just documenting my thoughts incase an Apple tech ever reads this …

1. Random freezes while sleeping (for me this happened in Tiger & Leopard).
I wish I had reported this issue to Applecare to get it on record when in warranty. It was always intermittent & impossible to reproduce on demand. I thought it was due to certain USB devices, but never managed to prove it. GET THIS ON RECORD IF YOU HAVE A WARRANTY.

2. Erratic processor behavior, (one disappearing on Dual systems). Freezing & sleep lockups can sometimes produce a grey screen with a 'no entry' symbol following the freeze.

3. Boot to black screen - this baffles me, the fans spin, the HD spins & begins it's early startup clicks, (not click of death style) but the startup goes nowhere and the screen stays black. Probably both CPUs failed? The fans never get chance to spin up to full blast.

I assume when in stage 3 all of the things Tenoch T said about it are true for my G5 (I don't want to test it in this 'dead' state) eg, no target disk mode, no Open Firmware, no Safe boot, no resolution by PRAM/ NVRAM resets etc.


Sadly I reached stage 3 last night, but weirdly this morning I booted first time with only one CPU.

I shall spend the next few hours calling Applecare and I shall also point them to this thread.

Thanks to all the help & advice - it's what makes using the mac pretty nice. I expect to be posting a little less since my G5 is slowly dying 😟

Thanks,
Drew

You are both in LA, maybe the temperature make the same things fail around the same time span?

I assume LA is hotter than my cool UK flat.
My Mac was assembled in Ireland for what its worth.

Hey Drew!
Yes I know how to use a volt meter but I don't own one.
My G5 is between:
1. booting up and freezing on the apple logo, with fans running normal then a minute or so later running full speed.
and
2. Booting up but no video, with fans running normal then a minute or so later running full speed.

I sometimes get case 1 and sometimes case 2, it happens randomly.

I'm going to put everything back and see if the cleaning did anything.

Good luck with your G5 and I hope it doesn't die soon.
Tenoch

Good luck with yours Tenoch T.

I'm avoiding using as much as possible, I can't use Final Cut Pro on one processor, since its benchmarked to run with 2. I could delete the FCP prefs, but what is the point when I can only get few hours usage before it locks up with no warning, and then I don't know if it will restart & boot or not.
It has happened right as I need to begin a new edit with a tight deadline too.

Applecare didn't seem to care that it was only 2 months out of cover, I'm booked in with the local Genius bar tomorrow so I'm hoping an actual person will care to listen to the fact that this started when it was covered. (my fans would fire randomly up in sleep mode etc…) I think I may have better luck on a weekday when the Applecare telephone team are in Ireland, not India.


If Whoopy or Ken773 are subscribed to this I'd like to hear whether you resolved it or just recycled it & got a new mac?