G5 2 GHz dual in the early 2005 dual 2.7 GHz

[bengi3]

I hate the Delphi LCS because it wasn't a great design in the first place and wasn't intended to be serviced, so I'd prefer to get rid of it. Some of the dual 2.5s had a Panasonic LCS and they were much better, but I didn't have any of those to swap over. Even if I did I doubt I would have done so because that system will still ultimately need maintenance that may not go well.

Here's what I did with my dual 2.7:

I disassembled the heatsink assemblies from a couple bad 2.0 processor modules and attached them to the 2.7 modules. I reinstalled the new air-cooled 2.7 modules and also a bodged LCS cooling pump. Why the cooling pump? Diagnostics and thermal recalibration fail on these if the LCS pump isn't running. So what I did was create a loop with the old hose, fill the pump with water, and set it out of the way as much as possible during testing. Once the pump's electrical connector was attached and the air deflector installed, I booted the Apple diagnostic disc and ran the basic suite of logic board tests to make sure everything relevant was properly recognized. Then I ran thermal calibration, which passed. After that, I shut it down, disconnected and removed the LCS pump, and closed up the case. It rebooted in OS X and has been running fine since. The fans rev up more frequently and a bit louder than they used to, but CPU temperatures are kept reasonable and there are no system errors or crashes like it used to have with the old LCS. Under normal use the computer does not miss the LCS pump.

I had considered doing the same with the Quad G5, but unfortunately the 970MP runs much hotter than the 970FX so it's not a great idea. Also the air heatsink for the single dual-core 2.0 and 2.3 modules is much larger than that of the old single-core modules, so it's not possible to fit two of them in the same case. So eventually I'll have to rebuild the Quad's LCS.

Did you leave the daughter pipes or replaced those too?

 

[Franklinstein]

The inside of my modified air-cooled 2.7 now looks exactly the same as any other air-cooled G5. There are no original pumps or pipes remaining.

 

[bengi3]

The inside of my modified air-cooled 2.7 now looks exactly the same as any other air-cooled G5. There are no original pumps or pipes remaining.

The inside of my modified air-cooled 2.7 now looks exactly the same as any other air-cooled G5. There are no original pumps or pipes remaining.

The pipe is the weird thing attached to the processor board and kept bond by two screws and thermal pad (not easy to take apart). I believe that the original can stay, but some guys suggest to swap this too.

 

[bengi3]

Made the final transplant along with new thermal paste, but the 2.7 runs too hot. I think I will go back to the liquid cooling.

This is what happens whilst loading a web page:



View attachment E134D66E-9A2F-4B3F-839C-CD3DA023DA14.MOV

 

[Franklinstein]

Mine is definitely louder, but it's not being used in a studio (partially because it's one of the models with the cheap noisy capacitors) so it's not a concern to me. It has the bigger video card so it makes plenty of fan noise already. It's about the same as an MDD G4. If the LCS could be readily replaced with PC parts it wouldn't be a big deal to keep the system, but the pump and the cooling blocks used here are special, so if they go bad you're out of luck: either spend lots of money on original replacements or do some custom fabrication. I would put that kind of effort into the Quad, but not the others.

 

[bengi3]

Went back to LCS. No chime. Back to air no chime. These G5 are a nightmare. Long ago I promised to myself to forget about G5s and then came this one from my university lab... what a frustration!

 

[demik]

Good luck mate ! Mine started to loose ethernet and now Firewire ports are not working anymore...

I'm starting to wonder if the caps on thoses are crap or dead. Will open it this week.

 

[Unknown_K]

Good luck mate ! Mine started to loose ethernet and now Firewire ports are not working anymore...

I'm starting to wonder if the caps on thoses are crap or dead. Will open it this week.

If that happened on a PC I would say some BGA balls on the controller chip are broken, eventually it will quit working altogether,

 

[demik]

If that happened on a PC I would say some BGA balls on the controller chip are broken, eventually it will quit working altogether,

Close, it got PCI cards and I got cards freezes in the past. Thanks for your help, I will open a different thread and not hijack this one further

 

[Franklinstein]

Went back to LCS. No chime. Back to air no chime. These G5 are a nightmare. Long ago I promised to myself to forget about G5s and then came this one from my university lab... what a frustration!

Yeah that's why I just left mine after I did the mod. These things are just too sensitive.

I decided to retest mine today and it's odd: if I run TenFourFox, the CPU temps (according to Temperature Monitor) get close to 80C but the fans stay fairly idle. If I run a video game, Safari with an old Flash site, iMovie, iPhoto, etc, the fans rev up normally and keep temps between 50 and 60C. If I run these apps with TenFourFox in the background, the fans rev up normally and keep temps down. If those apps are running while TenFourFox is the foreground app, temps go up and fans stay quiet. I don't know why this should be since Mac OS X (10.4.11) should be managing the thermal controls in response to its onboard sensors with no regard to what apps are running. I guess I didn't notice it much before because I don't use internet on this one. When the CPUs were reported to be near 80C I leaned the air deflector out slightly and touched the CPU heat sinks and they were only a little warm, not burning up as you'd expect if the CPU was truly that hot. After I shut it down I removed the covers and the CPU heat sinks were still pretty cool; most of the heat seemed to be on the small power regulator heat sinks, which were fairly hot. Either way i think I'll probably keep TenFourFox use to a minimum on this one.

 

[bengi3]

Ok. So I ended up buying two more processors. Although they were 2.5GHz not the 2.7GHz (I wanted the 2.7 because these were the original and because there is a sort of historical value, being the 2.7 GHz PowerPC processor the one with the highest clock ever installed on a Mac) I could rule out a couple of bad logic boards and resurrect this Mac, which I bought new, back in 2005.

I managed to calibrate the thing with the air cooling system and the original pump connected outside the case, however I had to rerun the calibration three times after swapping the two CPU and plugging another pump (with the first pump I kept getting the “intake fan speed error”, and before swapping the CPUs I got the “tafs out of range”).

 

[bengi3]

Case positively closed: the early 2005 logic board of the liquid cooled 2x2.7 GHz PowerMac accept the 2.0 GHz FX processors. See picture:

 

[bengi3]

Incidentally, should ASD be rerun if I replace  the LCS with air?