Hey everyone, have not been the the PPC section in a while and figured I would run this by you all. Back in 2012, I picked up a PMG5 2.5 GHz Quad with 8GB RAM and the FX5200. Used it for a couple years for photo editing and other activities. It went into storage maybe in 2015 or so. In Summer of 2019, I found it in the storage unit and wanted to fire it up for old times sake. It was SUPER LOUD, way louder than I remembered it ever being, so I was like "hey why don't I just replace the TP". I took it apart following some guide I found and reapplied the paste, put it back together and it does not boot anymore, it has a red light on the motherboard then shuts off. I gave up with it. Today I found it again and decided to revisit it, took it back apart checked over my work again for bent pins and such and could not find anything obviously wrong. Somehow someway I must have broken it, which is a shame, but it is what it is. I was wondering if maybe there was something stupid I overlooked that someone else has dealt with. Has not worked in 1.5 years and has not been used in ~6 years so don't really need it but would be cool if it worked again. Happy New Year!
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PowerMac G5 no longer boots after reapplying Thermal Paste
- Thread starter M3Stang
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Hi,
assuming that you applied the thermal paste without dirtying anything, it happened to me that the socket did not make good contact with the cpu. Sometimes it is enough to disconnect and reattach the cpu / lcs block with a little more decision and solve the problem. Remember to test the system only after having screwed back all the screws of the lcs. I hope I have helped you.
assuming that you applied the thermal paste without dirtying anything, it happened to me that the socket did not make good contact with the cpu. Sometimes it is enough to disconnect and reattach the cpu / lcs block with a little more decision and solve the problem. Remember to test the system only after having screwed back all the screws of the lcs. I hope I have helped you.
Thanks. I think it’s time to retire it then. I reseated it several times. I even saw that one of the cpu heat sink screws was not fully down so maybe it shorted on the case or something. I guess it’s done.
Last month, I did a full teardown of my DP 2.0 G5 because of spontaneous KPs and re-boots.
The assumption was the backside of the logic board, which had never been cleaned or re-pasted, was filthy and insulating dust was causing heat management issues with the northbridge (I re-pasted the CPUs in 2019).
After reassembling, the G5 would not start. At all. I took out the CMOS/BIOS battery (still the original), then re-seated it and reset the PMU down near the lower front of the logic board, near the lower bay of RAM slots. Still nothing.
Whilst still plugged in (the PSU did click when I plugged it back in, so I knew that wasn’t the issue (I dusted out and cleaned this, too), I applied pressure on the front-most PSU cable to the logic board — the one powering the front board (which has the power button, FW400, USB, phones, and LED). I did this while pressing the power button (no pattern, just pressing it and pressing it).
Suddenly, the system came to life and (mostly) booted (“mostly” because I didn’t have a full install of OS X in place, just a gutted old build which was dead, but still had BootX to begin booting). The front LED, however, was off, and pressing and/or holding it to force-shutdown was unresponsive.
I have an Apple Cinema Display attached to the DP 2.0, and that power button still powered up the system fine. Following boot, I individually tested the FW400 (with an iSight), the USB (with an iPod), and the headphone jack. The result was the iSight briefly shoned its green ready LED then powered down; the iPod woke up but would neither connect to nor re-charge; and the audio, using headphones, was scratchy and only in one channel.
I took out and checked the front PSU/board cable (attached) with a multimeter to test for bad connections on each of the 18 pins. All appeared to be fine.
I have since put that cable back in, and the outcome is the same.
As you may have noticed when you took apart your system, there’s a black plastic cap covering the board plug on the board side, which for me was very challenging (annoying) to remove. In trying to remove it, I have the hypothesis, still untested, that I damaged the solder points where the plug receptacle meets the logic board.
Once I know what to test for with the multimeter/what to expect from each pin test, I will try to check each of those solder points (I’m not an electrical engineer, so it would be wonderful if someone who knows that stuff or has board schematics to guide them can direct us on how to set the multimeter, where to place the probes (i.e., what is proper ground), and what values one should expect with what test).
If it turns out to be damaged solder points, I may or may not take apart the system again to repair the board and fix the solder. The system is again running, but now without a working front board. So long as I can use an external source (like the ADC, or a fruit-era/Sawtooth-era Apple keyboard with the power button included) to power up and shut down the system, I will live without the front board.
tl;dr: The front board connector may have been damaged during disassembly. As you put gentle pressure on the front cable down onto the receptacle, press and re-press (not hold) the power button to trigger a power-on. If this is successful, then it’s possible the board was damaged during disassembly (cracked solder would be my hypothesis).
What are normal temperatures for the G5 (970FX) on idle and load (Cinebench)?
Idle CPU A 52°C fan 300 RPM
Idle CPU B 47°C fan 300 RPM
Load CPU A (Cinebench 11.5) 75°C fan 350-780 RPM
Load CPU B (Cinebench 11.5) 75°C fan 350-780 RPM
Is it time to renew the thermal paste?
Idle CPU A 52°C fan 300 RPM
Idle CPU B 47°C fan 300 RPM
Load CPU A (Cinebench 11.5) 75°C fan 350-780 RPM
Load CPU B (Cinebench 11.5) 75°C fan 350-780 RPM
Is it time to renew the thermal paste?
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If you have a working Power Mac G5 in 2021 whose thermal paste has probably never been replaced, then it’s overdue for a clean-out (especially the logic board backside, inside the PSU, and so on) and new thermal paste for CPUs, the northbridge, and PCI controller heatsink.
Also a consideration for cooling efficiency is which CPU heatsink plate your system uses. Users report different heat-diffusing profiles between G5s equipped with the copper heatsink plates and the, I think, aluminium heatsink plates.
Your idle CPU is significantly cooler than mine is. My setup, the mid-2004 2.0 DP PCI-X 2 series (with PC970fx CPUs), is mated with copper heatsink plates. I also have three 3.5-inch HDDs running in front of the CPU intake fan, which generate their own heat, pre-warming all intake air. My idle temps tend to range between 63–68°C. Under load, however, I rarely ever see the CPUs get higher than 73°.
You may also want to monitor your Memory Controller Heatsink temperature.
Attached is what the backside wall looked like in my G5 when I took out the logic board last month to conduct a full clean-out and new paste everywhere. I assume the first two owners kept the tower at or near the floor (which, given its weight, is a conservative assumption). In the seven years I’ve used it, I’ve kept the tower about 1.5m above the floor. As you can see, there’s a ghostly mirror image of the logic board backside where the microfine dust of over 16 years aggregated.
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I dont have no prblem with the backside, because i have replaced the internals from a from a second G5 (my board was damaged for years and my case was in a much better condition.
The "new" board was in a perfect condition with nearly no dust. The rest was cleaned and controlled before build in.
Ouote from the Movie Soldier:
"My daddy was in maintenance and he had a saying, he used to say, "If it ain't broke, don't fix it."
I simply have three 3.5 HDDs standing vertically and physically spaced apart from one another. That’s it.
Could we stay on topic here?
It's probably a bad solder joint, maybe one of the power cables. You can get the boards online if you want to
put in the effort. Lots of G5's floating around. 5 years ago I saw about 20-30 in a store here in NM. All cheap. Store is gone now. Covid did it in
put in the effort. Lots of G5's floating around. 5 years ago I saw about 20-30 in a store here in NM. All cheap. Store is gone now. Covid did it in