PowerPC G5 Startup Issues

barnturkeys

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Original poster
Oct 20, 2017
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I am not too well versed with the internal parts or setup dialogue, but I will try my best to explain my issue.

One day, it wouldn't turn on. There were previous incidents where I would find the computer fans on full tilt and would manually shutdown.

I replaced the power supply and battery.

When I plug it in, I hear a click and a white light flickers near the power button.

I am not sure how to troubleshoot any more possible issues.

I read somewhere that you should take your PowerMac G5s for a walk in the woods and blast 'em when they're not looking. But I can't give up on her. Any help would be great.

Thanks
 

mp2017

macrumors regular
Sep 24, 2017
123
58
Unfortunately it appears as if the system board has failed. One of my systems had the same symptoms as yours and it turned out to be a failed system board. People have attempted to solve the problem by heating their boards in the oven or using a heat gun. Each with varying levels of success.
 
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Mac03ForLife

macrumors regular
Sep 19, 2017
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Washington, DC
This has happened to me before. I fixed it by turning the machine off, unplugging all the IO cables from the back (ADC, DVI, Power, and USB), then turning it back on again. After the light turns on, press and hold the power button for 10+ seconds. Then, after the light goes out, re-plug everything in as if you were doing it for the first time. Then, turn it back on. It should boot up normally. Let me know if it doesnt
 
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barnturkeys

macrumors newbie
Original poster
Oct 20, 2017
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Unfortunately it appears as if the system board has failed. One of my systems had the same symptoms as yours and it turned out to be a failed system board. People have attempted to solve the problem by heating their boards in the oven or using a heat gun. Each with varying levels of success.
Thanks so much for your reply! I might need a description of what I am removing.
[doublepost=1508506853][/doublepost]
This has happened to me before. I fixed it by turning the machine off, unplugging all the IO cables from the back (ADC, DVI, Power, and USB), then turning it back on again. After the light turns on, press and hold the power button for 10+ seconds. Then, after the light goes out, re-plug everything in as if you were doing it for the first time. Then, turn it back on. It should boot up normally. Let me know if it doesnt
Thanks for your reply! I will give it a shot, These are the ports in the rear, correct? I've been looking for a solid diagram of all the guts in my G5 to help me better understand what I'm working with.
[doublepost=1508507016][/doublepost]I want to add that there is no activity going on after I plug it in. Just a click and the white light flicker.

You're replies and help are greatly appreciated, I'll keep you updated.
 

mp2017

macrumors regular
Sep 24, 2017
123
58
Thanks so much for your reply! I might need a description of what I am removing.
[doublepost=1508506853][/doublepost]

Thanks for your reply! I will give it a shot, These are the ports in the rear, correct? I've been looking for a solid diagram of all the guts in my G5 to help me better understand what I'm working with.
[doublepost=1508507016][/doublepost]I want to add that there is no activity going on after I plug it in. Just a click and the white light flicker.

You're replies and help are greatly appreciated, I'll keep you updated.
My recommendation is to obtain another system. The chances of any lasting repair are small.
 

redheeler

macrumors 604
Oct 17, 2014
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There were previous incidents where I would find the computer fans on full tilt and would manually shutdown.
Logic board failure is not uncommon on Power Mac G5s. I had a Late 2005 model that did this a couple times at first, I would walk in and find the system had locked up with fans on full blast; soon it would power on but do nothing else (chime, boot, or output a signal).

So the only way you can resolve this is likely to replace the logic board, especially when the power supply is already ruled out as a culprit.
 

barnturkeys

macrumors newbie
Original poster
Oct 20, 2017
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Unfortunately it appears as if the system board has failed. One of my systems had the same symptoms as yours and it turned out to be a failed system board. People have attempted to solve the problem by heating their boards in the oven or using a heat gun. Each with varying levels of success.
Thank you! So, a mother board, system board and logic board the same thing?
 

barnturkeys

macrumors newbie
Original poster
Oct 20, 2017
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For the purposes of this discussion they are. It's the large board everything plugs into.
You're patience is appreciated. I know you recommended a new system, but I can't let this one go.
I removed the the logic board and flipped it over and discovered a whole different world. Any good diagrams of what I am looking at? Or is there a detailed diagram of the whole system?
 

mp2017

macrumors regular
Sep 24, 2017
123
58
You're patience is appreciated. I know you recommended a new system, but I can't let this one go.
I removed the the logic board and flipped it over and discovered a whole different world. Any good diagrams of what I am looking at? Or is there a detailed diagram of the whole system?
Is it possible you could provide us the specific model information? That would make it easier to assist. Without knowing I quickly looked up a picture of the system board and found the following. The red square is the area where the problem lies. It's thought the solder for this chip becomes brittle and cracks. Heating it up is supposed to reflow the solder so that it works:

DCP_6585.JPG


I used a heat gun and it lasted all of one day. I hated to scrap my system but reality was what it was. At least I was able to find people who could benefit from the parts.
 
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eyoungren

macrumors Core
Aug 31, 2011
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I hated to scrap my system but reality was what it was. At least I was able to find people who could benefit from the parts.
In June 2013 some time I walked into work to get started with my day to find the PowerMac G5 1.8Ghz with fans on full blast. I figured it had crashed so shut if off via the power button and then restarted.

Got nothing but black screen and revved fans. Tried everything and got nowhere. So at that point I decided it was either the logicboard or the CPU. My boss gave me the Mac and ordered me a refurb MacPro.

At home I searched eBay and found a logicboard/CPU for my model for $60 as one unit. I swapped the entire thing out and the Mac came right back. This board is older than the one it replaced.

Four years later and that Mac is back at work and has been doing the same things it was doing before. Only now it's being used by my coworker up in the front office. It's still very much alive and functional and is used every day.

I bring all this up because a dead logicboard doesn't mean the end for any system. I've replaced a few logicboards and each time the system came back. For $60 shipped my problem with my G5 went away and the system lived. Parting it out wasn't necessary because the new logicboard needed all those parts.
 

mp2017

macrumors regular
Sep 24, 2017
123
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I bring all this up because a dead logicboard doesn't mean the end for any system. I've replaced a few logicboards and each time the system came back. For $60 shipped my problem with my G5 went away and the system lived. Parting it out wasn't necessary because the new logicboard needed all those parts.
Replacement of the system board is an option. I recommended the OP replace their system as it didn't sound as if he was too familiar with computers. Additionally I can purchase a complete dual processor PowerMac G5 systems for approximately $60.00. It appears as if the OP took the time to pull the system board so he's already halfway through the effort to replace it.
 

AphoticD

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Feb 17, 2017
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It seems these logic boards were hit and miss on the 1.8ghz models. I had a similar experience with an original Dual 1.8Ghz G5, failing after 13 years.

If you find another same gen system for cheap, you could swap out the best parts and keep some other spare parts on hand in case of future failures (PSU, CPU, GPU, RAM, cooling fans, etc).

The tower cases can be resold easily as there is a market for them as empty shells for Hackintosh/PC builds.

On that point, if you are looking at some empty shells, I’ve seen that in many cases the logic boards are still inside because the seller is too lazy to remove it. This could be an option if you find one with a board of the same gen. You could then resell the case for what you paid or higher and get a “free” board out of it.
 
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barnturkeys

macrumors newbie
Original poster
Oct 20, 2017
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WISCONSIN
mm.jpg

[doublepost=1508809412][/doublepost]PowerMac G5 Model No a1047 EMC no 1969c
Pretty sure it's 2.5ghz
[doublepost=1508809450][/doublepost]
mmm.jpg
 

barnturkeys

macrumors newbie
Original poster
Oct 20, 2017
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I realize the dust balls are pretty extreme, I took the photo seconds after removing the logic board. I didn't know there was anything behind the board.
In all honesty, would simply removing all the dust bunnies bring this steed back to life?
 

AphoticD

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Feb 17, 2017
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I realize the dust balls are pretty extreme, I took the photo seconds after removing the logic board. I didn't know there was anything behind the board.
In all honesty, would simply removing all the dust bunnies bring this steed back to life?
Not likely. Dust won't cause anything other than higher running temps.. and it looks bad.

Once you've cleaned it up, look for any blown components and clean up any corrosion which may have built up from humidity.

The build up at the backs of the lower two power connections looks suspicious. Get some Isopropyl Alcohol on a cotton tip and see if that cleans up at all.
 

mp2017

macrumors regular
Sep 24, 2017
123
58
I realize the dust balls are pretty extreme, I took the photo seconds after removing the logic board. I didn't know there was anything behind the board.
In all honesty, would simply removing all the dust bunnies bring this steed back to life?
As already mentioned it's unlikely to do so if the problem is a failed system board. However if the system board is OK and it is merely overheating then cleaning up the dust could resolve the issue. Or the dust could be causing electrical shorts which would clear up after a cleaning.

If I had to guess I would say the system board has failed and cleaning it won't fix it. But the cleaning is free with the only cost being your time to do so and reassemble the system. Given how dirty that board is it just might be worth that time.
 
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barnturkeys

macrumors newbie
Original poster
Oct 20, 2017
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I realize some logic boards are made for one processor, but does the logic board have to be compatible with my dual 2.5Ghz?
 

AphoticD

macrumors 68000
Feb 17, 2017
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I realize some logic boards are made for one processor, but does the logic board have to be compatible with my dual 2.5Ghz?
I would try to find a board to match the same model number. I imagine that given it has 4 ram slots and not 8, it is a Dual 1.8 or 2.0Ghz. For guaranteed compatibility, I would use a board from another 7,3 with 4 RAM slots.
Introduced June 2004
Discontinued April 2005
Model Identifier PowerMac7,3
Model Number A1047
EMC 1969C
Order Number M9454LL/A (dual 1.8 GHz), M9455LL/A (dual 2.0 GHz), M9457LL/A (dual 2.5 GHz)
I have only tried swapping CPUs and components between model 7,2 G5s. Someone else might be able to confirm if 7,2 and 7,3 components can be swapped between boards as the 7,2s are more commonly found.
 
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