Q: Quad G5 Liquid Cooling Pump Chugging, nasty thermal disparity between cpu's

Doc,

You are following the same line of thought as I am. My original email to Danger Den was to ask for the specific dimensions of that universal cooling block in order to see if it would fit. They immediately responded offering to do a custom. It makes sense that it would be easy for them to do a custom top, as it is just a simple piece of plastic with a few holes and a seat for an O-ring. I sent them detailed drawings of what we need, but I have not yet heard back.

The next problem is plumbing. A company named Koolance has some fittings that I think will work to connect a block to the 5/16 ID tubing that fits the radiator and S-tube. Of course, if you're going to replace large parts of the LCS, you'll have more flexibility. I thought briefly about that approach, but worried that I couldn't make the thermal calibration process work. I think that you need to connect the fans and pumps of your new cooling system to permit the firmware and/or OS to control them as it does the existing ones. Is that right?

Jon

Jon,

I'm not sure how much of the stock LCS I'll have to use. I'm also not sure about if thermal calibration is dependent on a reading from the stock pumps. More experimentation is needed for sure.

And I still don't know if my processors are shot or not. I got a memory address error this am with the frozen copper block I was trying but at least I got a full 2 minutes before thermal hang.

I may just order those universal blocks and some fittings to experiment with while waiting for my replacement processor to arrive next Monday.

Doc

I forgot to ask if anybody knows if the ASD version 2.5.8 is the right version for thermal calibration of the quad g5's. It works fine on my earlier model DP 2.0 G5 but I can't test it on the Quad right now for obvious reasons.

Berzerkula,
My G5 kicks the fans on/off frequently. Any load kicks them on, but not high speed. Thermal Cal shows everything ok. I just replaced the cpu's and rebuilt the cooling system. The problem I suspect is air in the system and possibly needing more coolant, is there an easy way to bleed? Where did you buy your tubing? I wanted to get rid of the metal tubing and replace but my tubing kinks
thx

Berzercula,

The tubing I am experimenting with kinks too. I got it at Home Depot. The link to DangerDen.com in a couple of post back is a good source for tubing that doesn't kink. I plan to order some and get rid of the metal tubing too.

Doc

Ooops... my last post should have been directed at +Dual 2.5+ not Berzerkula... duh.

Sorry for any confusion.

Doc

ASD 2.6.3 for the G5 Quad. I wouldn't worry too much about thermal calibration if you are sticking with the same processors, mine still won't calibrate although the problems with the fan have gone.

Replacing the blocks would be a good thing for anyone carrying out the repair, I still think one of mine is suspect. Probably changing the entire LCS is too far since the system works quite well if all the components are working.

Hello,

The tubing I got from Sidewinder Computers. It's 3/8" inner diameter and 5/8" outter diameter. Tygon 3603.

For bleeding the system, I opened the system and put two lines into a container and started the pump until air was out of the system, then I sealed off one end, and left a hose in the container and lifted up the container until fluid was at the end that I taped off. Worked well. As long as you can use your thumbs to keep the system closed, you should be fine.

The above process requires you to use a piece of hose that won't be in the system. Should be a nice length to raise up and down in the container. That will be removed and you'll have to quickly use your thumb to close off the fitting it attaches to, so then the taped off hose can then quickly be reattached once tape is removed. Will probably get a tiny bit of fluid loss, but it'll be okay.

Hope this helps.

-William

Berzerkula,
thanks for the info. So what do you use to independently power the pump? And how do you hook it up?
thanks agn
Mark

Update:

Well the good news is I am posting this from my Quad G5. That means my processors are OK that the thermal shutdown was a fail-safe! Way to go Apple/IBM!!

The bad news is that I still am working out the details of repairing the LCS. My "band-aid" fix is the frozen cooling blocks I mentioned earlier. I have the processor boards installed without the LCS and have the cooler (off the self stuff) just sitting on top with a good dap of thermal grease. The temps are reading out right now is as I type at 101.8, 102.1, 107.9, 104.6 for the four core diodes (deg F).

I will continue to work on repairing the LCS and hope the the one I purchased is compatible that way I have a spare at least.

BTW - I did figure out that the system does not seem to care if the LCS is plugged in or not. I see no indication that it is needed. This opens up the way for a complete custom cooler with out having to figure in the stock pumps. Yay!

Temps still pretty steady... the highest I've seen any of the cores go is 116.8 deg F with just Safari and Temp Monitor running. I haven't tried taxing the processors yet though.

Doc

Dual 2.5 G5,

If you have the 2 pump version and thus a 12 pin connector, you can apply 12 volts DC to pins 1 and 2 and ground to pins 7 and 8, then apply 12 volts to pins 5 and/or 6 to run the pumps.

At least that worked for me.

Doc

Doc,

That is a very intriguing result! Thanks for doing that experiment and sharing the result. About how long have you been able to run the machine with your "frozen heat sink" solution?

I am still hoping that Danger Den will be able to create a custom cooling block at a reasonable cost, as I am convinced that my one clogged block is my only problem. However, I haven't heard back yet.

Your earlier post referred to eliminating the aluminum S-tubes and replacing with all-plastic tubing. I also tried that. I bought some very flexible Tygon tubing, like that sold by Danger Den. However, the tight space made it very difficult to avoid kinks even in the more flexible tubing. I may try again if I am able to use a custom cooling block, as that will allow me to eliminate one tubing size transition.

Jon

Jon,

I've been able to run the machine indefinitely by turning the case (still on it's side) so that the air inlets (front) is facing the a/c vent on the floor behind my desk. I turned the thermostat down to 68 to keep the cool air coming. I even ran software update and rebooted. So far, unless I tax the processors it stays cool enough. I was even been able to shut down last night and restart it this morning without refreezing the cooling blocks. I am very pleased that my processors are still OK.

As for the S-tubes, I still may leave those in. I never got around to ordering any Tygon tubing but I was thinking that if you made a couple of slow loops around using a bit of extra tubing you may be able to avoid the kinks. That will add to the volume of coolant and may even help. I just haven't gotten to that point yet.

Yesterday I opened and tapped the nipple fittings on the radiator and S-tubes and fitted some 8-32 fuel barb fittings from a Hobby Store locally. I may ditch this plan because the subsequent tube size ends up with a very small internal diameter. I got a self priming pump yesterday from Northern Tools (well my company bought it for me ) and as soon as I can get to Home Depot I will get reducers down to the 3/16 ID tubing I will use to prime the system. My plan is to have the pump inline between a big jug and the nipple on the s-tube and another line running from the nipple on the radiator back to the bucket. Running the pump should pull the coolant through into the system without air (assuming no leaks). When full I will simply fold the 3/16 tubing back on itself before disconnecting the pump and clamp at the fold and trim the excess. I think this will work. I hope .

I'll try to upload pictures.

Doc

Message was edited by: drpwilloughby

There might be a problem filling the system from a pump, in my case the only way to fully bleed the system was with the pump off manipulating the bubble from the pump to the top of the rad and out of the bleed tube. Of course I was using the fill and bleed nipples so you might have different results.

Usually ya don't fill a system from a pump. BOth sides of the pump need to be full then you have to close the system with fluid. Once the air is removed you quickly close the system. Priming is usually required.

-William