So a week or so ago, I serviced the LCS of my Quad G5, draining, cleaning, etc. All that is something of a story in itself, but I wanted to report here that the heatsink compound used on these machines makes a huge difference.
I originally sourced some SHIN ETSU X23-7783D, which I thought would be a higher-end compound than the generic stuff I have been using (silver-based, however, so not too, too generic). Two separate applications of the SHIN ETSU goop failed — the machine would not calibrate, let alone run well. So I decided to try the other stuff, using the same amounts and the same torques on screws, etc. This led to immediate success.
The moral of the story is that the tolerances on these machines are so delicate that it pays to use the right heatsink compound.
I originally sourced some SHIN ETSU X23-7783D, which I thought would be a higher-end compound than the generic stuff I have been using (silver-based, however, so not too, too generic). Two separate applications of the SHIN ETSU goop failed — the machine would not calibrate, let alone run well. So I decided to try the other stuff, using the same amounts and the same torques on screws, etc. This led to immediate success.
The moral of the story is that the tolerances on these machines are so delicate that it pays to use the right heatsink compound.