So the time came to service the LCS on my G5 Quad, which involves flushing the radiator and hoses, renewing the thermal paste, etc. It's a pain in the gluteus maximus.
One of the usual problems with these machines is that sediments in the coolant clog the microchannels and associated components in the cooling block. I duly cleaned mine up, refilled the system, and started 'er up — only to have a large temperature gap between the two CPUs. So I figured I'd take the offending processor apart and see what was the matter.
On taking the thing apart, I discovered that the microchannels were starting to plug up with sediments again, with the machine having run for no more than 45 mins. The radiator must be dirtier than I had thought, though I used a radiator cleaner and had taken the best part of a day to do the job right first time around.... I then had a brainwave.
"If the problem is the microchannels, what if the microchannels were removed?" thought I. I figured that if I was going to have to strip the thing apart again, I might as well do a little experimenting, and see if I could prove something to myself. So, I removed the internals in the LCS waterblock, which is a soft (silicon?) black pad, a hard plastic/ silicon microchannel insert, and a pink foam washer. I've attached a pic of them removed (they are now stored in a bottle of distilled water).
I then reassembled the LCS without these internal components, i.e., with the hole where they went empty as in another attached pic.
I then reassembed the lot, booted, and what do you know? The thing works perfectly, at the moment at any rate. I've attached a screenshot of the CPU temperatures over a five or six hour period today under varied levels of activity.
Iam not sure I will leave it this way, but at the moment, the machine appears to be working as well as it ever did. Temperatures are about normal for a G5 Quad (Processor is set on Automatic). While posting, I took a shot of the current temps in numbers for posterity.
Unfortunately, it fails thermal calibration in ASD2.6.3, which reports that the readings are out of specification. So I have to operate under my previous settings.
Edited by beachycove, 05 January 2017 - 01:28 AM.