Quad 2.5 thermal paste reapplication.

HI all,

I have to admit that I went out and bought a refurb MacPro and tricked it out before I dared to attempt this with my BFF quad 2.5 PowerMac. I got a:

long handled T 4 mm ball hex,

Long handled 3mm ball T hex,

Ceramique Arctic silver,

92 % Alcohol,

cloth wipes,

ESD pad,

Grounding strap and braid

a magnetizer:

and girded my loins as I was finally going in.

The issue I had was that my CPU A was running 20 C higher than CPUB at idle. I had to cut my power in half to get it to run without KP/s or just too loud of fan noise.

I have to report at least partial success. My cpu A now idles nicely at 39-40 C My CPU B, however, which had run at 39 c now idles at 47-48(grrr)

The fans are still too loud but , with the computer running all 4 CPu/s at 100% for hours, my highest temps on either CPU was maybe 65C

I am hoping that Arctic Silver's claim that it can takes days of run time to properly set will come true and bring down that cpu B to lower temps at minor workloads. The upper temp problem I solved and the most used CPU A is nice and chill already. If CPU B does not fall in line in a month I will not hesitate to pull it again and redo CPU B only as it is very much easier than I had feared. If you are calm, the job should take no more than an hour.

First My computer has the dual pump (non Delphi) LCS.

One: follow the steps for LCS screw removal or loosening(many will stay on and not fall out if you just leave a tiny bit of thread engaged ).

Two: pull the LCS straight out.

Three: simply remove all the that screws look like they are holding the copper heat sink( if you have removed every screw you can see then you have done it right).

Four: Remove the two screws at each end of the cpu board.

Five: Pull the cpu board and heat sink up and off to the side of the LCS

Six: Flip the board over(note the pins that you must not crush in handling) and see the dry paste over the little CPU die.

Seven: clean old dried paste off the die with alcohol or Arctic Silver's special fluid.

Eight: Clean the copper shim on the LCS the same way

Nine: Remove the dust on the pcb with an alcohol wipe if you can't stand too put it back in dusty) but know you risk brushing the pins if you are not careful.

Ten: Look up your CPU on Arctics Silver's website and follow their instructions exactly(this is where I screwed up I think as while I did use a credit card to "tin" the LCS copper shim I did not use a specific pattern and amount on the die face). Having just done this adding 2 x 3.43 GHZ six core Xeon's to my new MacPro....Grrrrr...I have no excuse).

11: Replace the CPU board by sliding it into its spot so that the heat sink goes in just right.(since you are doing it one at a time you have a model right next door). Tighten down all the screws. I went around as if I were changing a tire).

12: Repeat all the steps above for the other CPU board.

Next, replace the lCS in following the service manual again (Scribed has one). Mind the power cable that goes under the LCC. I scared myself silly when the LCS dropped too fast for my taste onto the guide standoffs. I had to have a friend push down on that cable a bit and when its support was gone: down went the LCS. Gently rock it from side to side a few times. Finally, replace or tighten all the screws in the exact order specified in the manual.

Renumber to put back the battery, which I should have had listed as step one. I didn't and it booted but my fans reved up and I thought I had failed.

This brings me to my question. I am hoping BD Aqua reads this but anyone feel free to jump in. Since my fans were reving too fast after I booted with the battery, I decided to make sure my 2.6.3 ASD boot disk worked and….it didn’t.

It turns out that my cherished 2.6.3 was simply a cruelly mislabled 2.5.2 and, as such, did not work.

Can anyone give search terms that will get me a real copy?