MP 1,1-5,1 Messed up with ArctiClean. Any harm for the Northbridge?

[Tommi14]

Hello everyone,

I did the following maintenance for my dual CPU 4,1->5,1 Mac Pro:
-repasted the Northbridge
-exchanged the factory Northbridge rivets to the famous white ones
-updated CPUs from E5520 to X5675

This was my first repaste job ever and I think it did not go exactly perfectly right. The computer seems to work more or less perfectly. However, I am worried that I did some harm to it.

I made (at least) a couple of mistakes when cleaning up the Northbridge:

-I think I might have forgotten to wipe away loose old paste before applying the ArctiClean 1.

-After applying one or two drops of the ArctiClean 1 onto the metallic area of the Northbridge, I accidentally let some of the cleaning fluid mixed with the old paste to escape to the green area of the Northbridge. What's worse, the mixture managed to surround the row of four small ICs on the green area. I did my best to clean up the mess but there was no way to perfectly clean all the residue between the tiny IC contacts.

The rest of the maintenace went according the plan.

The temperatures reported by Macs Fan Control at idle before the maintenance (with 10 years old factory paste) and after the repaste job and the CPU update were/are

	Before	After
CPU A Diode	40	40
CPU A HeatSink	37	39
CPU A core from PCECI	49	44
CPU B Diode	35	36
CPU B HeatSink	32	33
CPU B core from PCECI	42	37
Northbridge Diode	67	70
Northbridge Heatsink	55	58

Questions:

-Can ArctiClean (mixed with old paste) do harm to the ICs on the Northbridge?

-Since the computer seems to work ok for now, can it be assumed that the ArctiClean mess did not do any harm to the Northbridge? Or is there a possibility for later problems with this, such as crashes, shortcuts, smoke, fire? ? What is the worst thing that can happen?

-After the repaste job and the CPU upgrade, the Northbridge temperatures seem to be a couple of degrees of Celsius higher than with ten years old factory paste. Is this because of the faster CPUs?

Thanks in advance!

Tommi

 

[h9826790]

Don't worry, the cleaner dry up quickly, and the thermal paste is designed not to damage the electronics.

If the graphic card can survive with this amount of thermal paste (watch from time 5:00), your NB should be fine.

Anyway, there are few reasons can affect the NB temperature.

e.g. the new rivet spring is weaker, therefore, lower mount pressure.

Or as you said, the faster CPU may throw more job into it. Therefore, a bit warmer than before.

In any case, 12°C between the Diode and Heatsink is normal. Your thermal paste application looks OK.

If you want the NB run cooler, spin up the fans a bit can help a lot.

 

[Tommi14]

Ok, thanks!

Although, now I began to think that maybe I applied too little thermal paste on the Northbridge as I tried to follow this video. ?

 

[mattspace]

In any case, 12°C between the Diode and Heatsink is normal. Your thermal paste application looks OK.

I've nearly always had 15c between Diode & heatsink, both with the original factory paste, and with both repastings I've done. My suspicion is that people with very low deltas, or very low NB temps are single processor, or simply don't have enough stuff connected to / installed in their machines - I know mine scales depending on how many drives, and how much IO I'm doing.

Right now, 28c geographic ambient, 34c system ambient, 72c / 57c - Diode / Heatsink.