MBP inconsistently overheating, recommended repairs are overkill

I bought my 2.8 GHz Late 2008 Macbook Pro two and a half years ago, and just love the thing. The thing is, within the past two weeks, the CPU/GPU/heat sink temperatures have been increasing far beyond what they had before under any type of load (usually when using the discrete GPU). I only started noticing when certain demanding games on my XP partition forced the computer into sleep mode.

Making it much worse, I had carelessly exposed the computer to humid air many times during its lifetime, unaware that it would set off "water sensors" inside the case. This, of course, voided my warranty. According to my local certified Apple dealer, the way a repair would work is that they would send it to an Apple facility, and they would rebuild it, replacing the logic board and upper case because of the water sensors, regardless of whether that was actually causing the overheating. This would cost $1400, possibly wipe my hard drive, and probably be an affront to my sentimental attachment

I took the computer home from the shop today to back up my data and figure out what to do next. Oddly, the overheating seems to have stopped, at least for now. I don't know what they could have done during the process of looking inside and checking behind the fans that would have stopped the problem, but I'm worried about it happening again.

My questions are:

1. What are the chances of humidity-related damage causing overheating and no other noticeable effects? How long can corrosion continue after exposure?

2. What other causes could there be for this inconsistent overheating?

3. What are the chances of overheating causing permanent damage despite the automatic sleep mode? (Of course, if they would just replace the logic board anyway...)

4. What kind of places can I turn to that would look for the cause of the problem and repair it (or add thermal grease, clean it out, so forth)? What are the chances that they could replace a damaged sub-component of the logic board instead of the whole thing?

If there's no decent way to repair it, I might buy a desktop for my games, and keep this one for internet and email purposes. Even when it was acting up, it wouldn't get that hot while using the integrated graphics card. In that case:

5. If I waited a few years to get it fixed, would the price go down, or would they run out of parts and be unable to fix it at all?


I have no decent desktop to fall back on, so any advice is appreciated. Thank you.

how hot is it actually getting? does it shut down by itself? have you checked to make sure the fans are spinning/are not blocked due to excess dirt? what are your ambient temps?

water can really mess up a motherboard, and kill all sorts of things.

As for repairs - if it is the motherboard - it isnt worth it. buying a new laptop is more economically viable.

If you are very technically able you could try reapplying the thermal paste to the CPU. doubt it would do much difference.

The CPU would get up to 150-160 F for things like youtube, over boiling for games. It seems more reasonable now at about 130 F max for youtube.

I specifically asked the technician to look for dust in the fans, and he found none. Perhaps a fan is acting up, and this got it working again? If it overheats again I'll use a fan control program to test them independently. I hope that is the problem since it's pretty much the only part I can replace.

This Macbook is not overheating. what you are seeing is Flash using a lot of the CPU, and therefore more heat is generated. try blocking Flash.

Games are obviously CPU heavy aswell, more so than Flash usually, and therefore run hotter. Put it this way: encoding a video with Handbrake on my Macbook gets the CPU up to 95ºC. Its absolutely fine.

If your Mac starts to shut off after periods of hot running, or has issues waking from sleep, and you can hear the fans going mad, that is cause to worry.

150 F is within normal temperature conditions. Remember, a Mac is not a Windows gaming rig, overclocked to extreme, where you have to worry about airflow and CPU temps. Apple's engineers have designed the Macbook so that it can dissipate heat in a small amount of space. Very well, i might add. Laptop's run hotter than desktops.

Again, if it starts shutting off intermittently, this is cause for alarm.

I know, it just seemed hotter than what it would get before. And it did start occasionally going into sleep mode and refusing to come out for a few seconds during games.

Maybe the SMC was just refusing to spin up the fans like it seems to do sometimes. I tried a fan controller program to keep them at max speed during a game, and the temps seem decent enough so far.

In any case, I'll probably buy a backup disk, and keep it away from humidity.

Nervousness said:

Maybe the SMC was just refusing to spin up the fans like it seems to do sometimes. I tried a fan controller program to keep them at max speed during a game, and the temps seem decent enough so far.

Click to expand...

Bad idea. uninstall the SMCfancontrol, and reset the SMC. This program will degrade your fans.

Apple's engineers have designed the Macbook so that you don't need to monitor fan speeds and temperatures. the fans run appropriately depending on the temperature the cpu is at in real-time, like every other notebook on the market.

Intel-based Macs: Resetting the System Management Controller (SMC)

Do this whenever you have sleep problems.

Stop worrying about temps.

I tried resetting both the SMC and the PRAM, and at first it ramped up the fans, but then it just went back to ignoring the temperature like I've seen it do many times before. Is there a way to verify or reset the SMC firmware?