2006 MBP – Issues with GPU temperature after logic board install

[reezekeys]

I'll try not to make this too long. My daughter spilled lemonade on my MBP (15" Santa Rosa 2.2Ghz). I removed, cleaned & re-installed the logic board and it seems to be working OK. Wow did I dodge a bullet, I feel very lucky (so far at least).

Since it was recommended to clean off the old thermal compound & re-apply before installing, that's what I did. I've only done this once or twice in the past so I followed instructions to not put too much compound on – a thin layer that I spread with some saran wrap on my finger.

After getting things going, I downloaded a temp monitoring app (Marcel Bresink's "Temperature Monitor" ) and things look good except the "Graphics Processor Temperature Diode" is always a lot hotter than everything else. Right now it's at 60 celcius – most everything else is between 37 to 48 celcius. And this is WITH smcFanControl running, with the minimum fan speed hiked to 4000 rpm. At the default speed I saw the GPT Diode closer to 70 celcius with the computer not doing any heavy lifting at all.

Since I never monitored the temps before I had this accident, I can't say for sure that the GPT diode is running any hotter than it was before. I've googled and seen some references to this particular item running hotter than everything else, so it could be more or less normal. But, since I'm not super confidant about my laying-on-of-thermal compound, it might be nice to have a few others here either corroborate my experience with the temp readings I'm seeing, or maybe tell me to tear this sucker apart again and re-do the thermal compound application!

To clarify things a little more, the motherboard in my MBP was just replaced by Apple under the extended warranty for the bad NVIDIA graphics chip – so presumably I don't have one of those anymore.

Also, for the moment I'm gonna let the smcFanControl keep the fan speeds bumped up a little bit until I'm clear on whether I actually have a problem or not. TIA for any replies!

[Tommie Milwaukee]

Make sure all of the temperature sensors are connected. I believe there are 2 or 3 of them in this machine.

[reezekeys]

Pretty sure everything is connected – otherwise wouldn't I see readings of "0" or an impossibly high number? The temp figures all rise & fall as the computer works.

I have a few apps going right now:

[reezekeys]

Playing some Flash video in Firefox, the fan was at around 5400 rpm:



Do these temperature figures look abnormal?

[Spock]

Do these temperature figures look abnormal?

No, not for running a processor intensive application.

For example my 13" MacBook Pro 2.4 GHz Core 2 Duo running FAH @ 100% = CPU 1 85°C, CPU 2 81°C.

Hope that helps.

[reezekeys]

That helps a lot, thanks!

[DRR]

Run something processor and/or graphics intensive for 5-10 minutes and monitor the temp. If keeps rising until it crashes, there's a problem.

If it holds steady after a while and keeps running, then you know it is properly transferring heat. Temps themselves are not too telling, but those temps do not seem abnormal to me.

[reezekeys]

DRR - thanks for that suggestion, it makes a lot of sense. I'll try converting some video later, I think that should give things a good workout.

I had my computer on a gig last night (I play music, use it with a USB keyboard & virtual instruments) and things went fine. Since fan noise is a non-issue due to the volume levels of the band I play with, I set the minimum speed to 4000 rpm. Running a bunch of virtual instruments does not seem to tax the processor much, but I see no downside to using smcFanControl to keep things a little cooler anyway.