MBP + New logic Board + Heat problems

Details: MacBook Pro Core2Duo 2.4 (late 2007)

Back in November I had a problem where the computer sudden didn't turn back on. The logic board was replaced and everything was fine.
Here is the thread for that: http://www.mac-forums.com/forums/apple-notebooks/175055-mbp-not-booting-not-awaking-sleep-mode.html

That same week I purchased a 27in iMac and well lets just say the MBP (MacBook Pro) didn't get used much.
Since then I've started to use the MBP more often and i have notice; when ever i am playing a video or game the CPU temperatures increase to 210+.

This heat problem never happened before the logic board was replaced. I took it to the Genius bar today and they ran a few quick test and said hardware wise it appears fine. Unfortunately they only warranty the board for 90days after the replacement. The offered to do more extensive test for 85.00, and that would go towards the 310.00 if they figure out the problem and repair it.

I really don't want to spend another 310.00 dollars on this computer...AGH...
Anyone have any suggestion?

You could sell it and buy a new one.

13131jonny said:

You could sell it and buy a new one.

Click to expand...

Thought about it.

I called a Apple authorized sales/service center (non apple store).

They quoted 100.00 for diagnostics and that goes towards the repair.
If I decide not to repair it, then it can go towards the price of a new Apple computer (from there store).

Still not sure what to do...

Sounds to me like when they fixed it the first time, they failed to properly apply the heatsink... maybe its too much or not enough of the thermal paste. In any case since the warranty is out for the fix and you are on your own... I think I might just pop open the computer and try to reapply thermal paste to the heatsink on the logic board... at this point what do you have to lose? If you sell it you aren't going to get a good price since you will be selling a half working computer... and it would be a shame to pay someone a hundred buck for something you could do yourself for a couple of hours work and 5 dollars of thermal paste.

thomas998 said:

Sounds to me like when they fixed it the first time, they failed to properly apply the heatsink... maybe its too much or not enough of the thermal paste. In any case since the warranty is out for the fix and you are on your own... I think I might just pop open the computer and try to reapply thermal paste to the heatsink on the logic board... at this point what do you have to lose? If you sell it you aren't going to get a good price since you will be selling a half working computer... and it would be a shame to pay someone a hundred buck for something you could do yourself for a couple of hours work and 5 dollars of thermal paste.

Click to expand...

Good idea.

Yea, I had it open last week when I installed the new HD (500GB 7200RPM) and I didn't bother checking anything else out. Should have.

Since I'm pretty comfortable with opening it up, all i need to do know is figure out how to take the heat sink off the cpu.
I already have some "Arctic Silver 5 Thermal Compound"... Maybe I can figure this out my self...

So i opened up the MBP again, and it appears i would have to remove the entire logic board to access the CPU.

If you still have the machine open, check the fans and also the thermal sensors. I don't believe Apple replaces a logic board and the CPU assembly separately when they swap out the board. In other words, the board they replaced your original with included the CPU assembly, GPU, and anything else that's mounted to it. It's possible the problem could still be a poor application of compound but it could also be their failure to attach the thermal sensor wires or hook up the fans.

Regards.

chscag said:

If you still have the machine open, check the fans and also the thermal sensors. I don't believe Apple replaces a logic board and the CPU assembly separately when they swap out the board. In other words, the board they replaced your original with included the CPU assembly, GPU, and anything else that's mounted to it. It's possible the problem could still be a poor application of compound but it could also be their failure to attach the thermal sensor wires or hook up the fans.

Regards.

Click to expand...

Both fans work, spins from 2000-6000 RPM just fine.
The tech at the genius bar ran a sensor/fan check and it all checked out fine.

Maybe it is the compound on the CPU, idk.

So i'm correct when i say, the entire logic board must be removed in order to check the heat sink?

TomTomTuning said:

So i'm correct when i say, the entire logic board must be removed in order to check the heat sink?

Click to expand...

That I can't tell you for sure. However, the folks at this site have step by step instructions for doing most anything in the way of repairs on just about any Apple made product. Suggest you go there and look up your model MBP, and find the step by step instructions for various removal of parts.

Let us know.

Regards.

I found iFixit yesterday but there website was down for maintenance. Thanks for the reminder, i will check it out right now. (there site is back up)

Alright, so I finally decided to take the MBP apart and take a look at the CPU and the heat sinks.



I cleaned off the globs of paste, then spread a thin coat of Arctic Silver 5.

But unfortunately the problem still appears to be there.
I ran a youtube video while my CS5 bridge was processing some thumbnails, and it it's 210f (98.8c). CPU loads were 60-85%

But for some reason, the fans don't increase in speed right away, when the CPU temps increase.
Not until other temperatures increase.
If i play a long youtube video, where other components temperatures increase, then the fans speeds increase.
But this happened before to days changes as well.

I know you said Apple checked out the thermal sensors but it sounds like that may be the problem. Those fans should start kicking in almost right away before the temps begin to rise that high. It might be that the sensors need calibration. Dig around and see if you can find something out about that. You might even try to get hold of a service manual for your machine if possible.

Keep us posted.

Regards.