Fan speed not increasing when cpu/gpu runs hot (causes black screen)

Before calling Tech Support, run the extended version of the Apple Hardware Test to see if there is an error message that would indicate some sort of a hardware problem with either the thermal sensors or the fans. Even if nothing shows up, it will be helpful to establish whether or not the AHT shows anything. It doesn't sound right that the fans don't speed up to cool the machine.

Good luck!

I face exactly the same fan/heat/SMC problem - no solution yet.

MBP late 2008 2.4 GHZ 320/7200 4GB

Just to add I also have the same problem. Happened to me on both Fallout 3 and Crysis. I'm getting an replacement machine next week. But this wasn't my reason for exchange, my MPB has a backligh flickering problem.

If these two things are related, I don't know...

For everybody on this thread, you might possibly have the NVIDIA chip problem:

http://support.apple.com/kb/TS2377

Perhaps this might be contributing to the fan issue--I really don't know. It would be covered by the warranty, and probably worth asking about.

Good luck!

isn't this related to the early macs with the 8600? not the 9600.

You are right! I was not paying attention to which Macs were at issue here. This has to be some other issue.

Thank you for pointing this out.

I keep sounding off about this in every thread I see it mentioned because it's really a problem for me.

I have had this occur with Postal 2, Eternal Lands Client, and 4x4 Evolution 2. My Macbook Pro was manufactured Nov. 5th and I received it on the afternoon of Nov. 13th, purchased from the Apple online store.

The screen doesn't just go "black", the backlighting actually goes off. The audio tends to loop. If I let it sit for a while I find "NVChannel(Display):" timeout! errors in the log.. But nothing indicating a panic, crash, or hang. Most times there is NOTHING in the log which is very disconcerting obviously.

I ran an 8 hours extended looping hardware test with the AHT CD today and it found no problems.
Tech Tool Deluxe find no problems either, for whatever that is worth. Yet it seems if I play any OpenGL based game I get an unpredictable, random dead screen and audio loop.

With the various talk about temperatures, I find that it happens even if I just turned the computer on. It takes about 30 seconds to boot, and if I start a game immediately it often has blacked out immediatley.. No time to get hot. iStat Pro reports temps not even getting far past 65 sometimes when this happens. Full screen or windowed mode, still happens. But only with games. Any kind of video or screen savers or anything, no problems. Also, only with the 9600M GT.

In another thread people have had success with exchanging their units. Not sure what happens for me having bought a CTO online.

I just did some more testing and I have to take back what I said about the temperature. After doing a PRAM reset, I tried what for me is the surest thing to a black screen - Postal 2 w/9600M GT. The fans kicked in right away after starting the game and I played for a few minutes with no blackout. I quit the game and started it up a while later and the fans did not come on even after playing for a few minutes. I quit the program out of nervousness feeling like an impending blackout was on the way. I checked iStat and my GPU diode temp was at 91°. So there is something erratic about the way it is or is not turning on the fans when using the 9600M GT.

On a further note I have a console full of all kinds of errors and crashes - things that don't really show up while using it. Windowserver "port death" errors, report of a missing image called "Caution" every time I open system preferences, screensaver server crashes, just all kinds of crazy stuff. No amount of disk repair or permissions repair has made a difference.

The question remains that if it's a fan control issue, which would be software based assuming the temp sensors are working (which they appear to be since people can see the temps going up high), then why are people resolving the issue by exchanging their computers? There's a thousand possible answers for every wonderment on this I guess. Official word from Apple would be very welcome.

I've been fighting with this too, but only in Bootcamp, mainly because that's where the GPU-intensive stuff in on my machine.

I called Apple the other day and they had me reset PRAM (or whatever it's called now) and I fired up Windows and LoTRO. Played fine for 30 mins or so.

Went to work, which meant running OS X all day, and later on I went back into Windows to see if it was still better. No fans, black screen after a few minutes.

Called up Apple again and they said to +reinstall windows+ and the bootcamp drivers (does that ever work?) Two days later, I've finally got LoTRO reinstalled and patched again and it played fine, with fans blasting for 20+ minutes. I cycled in and out of OS X and fired up the game again. No problem this time either.

I'm going to keep checking on this and I'll report back if anything changes. I never buy the "just reinstall windows" line, but...

It's been a few days, and it happened again today. The "reinstall windows" method worked about as well as I suspected it would: It didn't.

Going to the bar to talk to a genius.

Same problem here, fans never go faster than 2000 rpm and using the 9600 increases heat way faster than the 9400 which leads to a crash. I'm not a gamer but installed a game to test if I'm affected and I am.

My problem is that in Spain there is no genius bar or anything similar, and getting a replace means to me being without the MBP for several days. Working as a freelancer this is not an option to me. Hope this issue can be fixed by firmware/software update but I'm concerned to the fact that the CPU is always working hotter than it should.

Also not being able to use hardware I've paid for is unacceptable. This computer is pricey and you expect to get what you pay for.

Started noticing this as well...

I've got some old games on my PC side that I've been playing. Grand Theft Auto Vice City and the like...

Fans kick in, but the computer gets crazy hot. The WASD keys are painful after a while, computer performance suffers as a result.

Going to run a test with Civ 4, see if games on the mac side cause it a problem as well.

Let us know how it goes.

For now, I've been using smcFan as a workaround, http://www.macupdate.com/info.php/id/23049

It simply allows you to set the minimum fan speed, the computer is louder, but it is cooler.

Bonus, is when you restart, Windows maintains the minimum fan speed.

I've been recording fan temps, on the mac side, I see 65C often. On the windows side, things are failing when the temp gets up to 72-76C on the GPU!

Crazy hot, burns my fingers on the keyboards hot. For whatever reason, the fans are dialed lower in this macbook iteration, and they're not terribly responsive to the temperature increases on the PC side.