Upgraded MBP HD, fans now out of control

[thxdave]

I have a 17" MBP (C2D, 2.33GHz,667FSB) and replaced the original 160 gig Hitachi HD with a newer 320 gig WD3200BEVT-222CTO. As a baseline metric, the fan on this MBP would rarely ever come on. I have iStat installed and the fan speed mostly stayed around 1600 to 1900 rpm and was inaudible.

From the moment I powered up with the new HD installed, the fans spun up to 6000 rpm and stayed there for several minutes. They eventually spun down into the 3000-4000 rpm range but would stay there in spite of the fact that the internal temps are ALL below 100F, again according to iStat.

I reset the PRAM (no change) and did a few restarts, but it seems to stay at a these higher revs. The aluminum case is not at all warm and is almost cool to the touch (very cold here in Fla. today). In contrast, the original HD config almost never caused the fan to speed up unless I was doing some very heavy HD activity. So, I know the fan system worked properly under the old HD but this new one has it confused.

While I was typing this, I put the MBP to sleep and the fans spun down. When I woke it, the fans remained at a (relatively) low speed of 2700 rpm (still higher than they were normally be with the old Hitachi HD). It's sitting here now with nothing running except BG processes (no apps) and it still has the fans spun up to 2900+ rpm. During the last 5 minutes, it has started creeping up to 3400 rpm. I'm beginning to think this thing is posessed!! ;-) Any suggestions as to what caused this new behavior?

Finally, I used CCC to clone the Hitachi over to this new WD drive. Could there be some data carried over from the old config that is now confusing the hardware? Just a thought....

Dave

 

[Eidorian]

Have you tried resetting your SMC?

 

[thxdave]

No, didn't try the SMC as of yet. I looked at that link and all the models listed were either iMac or Mac Minis. Would my MBP also benefit from the SMC reset? Is the procedure the same for MBP's? I have no peripherals other than the power cord attached.

 

[Eidorian]

No, didn't try the SMC as of yet. I looked at that link and all the models listed were either iMac or Mac Minis. Would my MBP also benefit from the SMC reset? Is the procedure the same for MBP's? I have no peripherals other than the power cord attached.

Don't forget to take out the battery...

The procedure is the same otherwise.

 

[thxdave]

Okay, did the SMC reset, let it sit for about 5 minutes without battery or AC adapter power. Put battery back in, attached MagSafe connector, powered up and I thought problem was solved. However, I got an initial slow ramp up of fan speed to just over 3000, then it slowly came back down to 2600 rpm and is VERY slowly coming down into the 2500 range. As I said initially, this thing never got much above 1900 rpm (and was inaudible) until I did some "heavy lifting" with the CPU and/or GPU. So, anything above those speeds seems out of the ordinary. I'll keep an eye on it and maybe somebody else will have a suggestion.

One other data point to offer: I called a Mac buddy of mine and he suggested booting off of the original Hitachi drive which is now sitting in an external, bus-powered Firewire case. This made sense since all the original system and program files are still on it. Unfortunately, this made no difference either and the fan still spun up abnormally and stayed there. This is weird.....

 

[Eidorian]

Have you taken a look at CPU usage as well under All Processes in Activity Monitor?

 

[thxdave]

Yup, iStat showed no spikes in CPU activities.....one of the first things I looked at, actually.

 

[convergent]

This sounds exactly like a problem I had with a PowerMac G5 last year. I bought it used, and from the moment I got home with it the fans were sounding like a plane taking off, but would go up and down kind of out of control. I took it to an Apple servicer and they were able to fix it by "calibrating the logic board". I basically had to pay for one hour of labor. I should note what when I queried Apple about the problem they were telling me that I'd need a new logic board, which would have cost more than I paid for the machine. If you are under warranty, I'd contact AppleCare to have them check it out.

 

[thxdave]

I finally solved the mystery.....and it was my fault all along. I opened up the case again tonight to try to figure out what was wrong and I discovered a slightly loose connection. When I originally opened up the chassis, I tilted the keyboard assembly up and rested it against the screen without disconnecting the ribbon cable that connects it to the logic board.

Apparently, I had dislodged the connector just enough to loosen it from a couple of its' pins but not enough for it to come completely loose from the connection point. This was enough to confuse the fans, I guess. Thanks guys for all the suggestions and I'm happy it didn't cost me any money. BTW, this WD HD boots up to my desktop several seconds faster than the old Hitachi 160 gig HD.