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hellobenny

macrumors newbie
Original poster
Apr 26, 2008
19
0
Hello,

I have a problem. Basically, after the fans rev up to 6200rpm, the rpm stays there and never comes down, even after the computer is sitting idle for awhile.

I installed the smc update and am using coolbook to try to avoid core shutdowns. Is anyone else having this problem? I'm going to try replacing the thermal glue tomorrow, to see if that helps, but it seems somehow unrelated to me. I'm using smcfancontrol to monitor the rpm of fans.
 

NC MacGuy

macrumors 603
Feb 9, 2005
6,233
0
The good side of the grass.
Hello,

I have a problem. Basically, after the fans rev up to 6200rpm, the rpm stays there and never comes down, even after the computer is sitting idle for awhile.

I installed the smc update and am using coolbook to try to avoid core shutdowns. Is anyone else having this problem? I'm going to try replacing the thermal glue tomorrow, to see if that helps, but it seems somehow unrelated to me. I'm using smcfancontrol to monitor the rpm of fans.


First of all I'd get rid of SMC fan control. Uninstall it totally. You can always add it later if you like.

Use iStat pro to monitor fan speeds and see how it works then
 

hellobenny

macrumors newbie
Original poster
Apr 26, 2008
19
0
Thank you NC_MacGuy for the suggestion, I tried it out but that did not fix the problem. The fan still spins at 6200rpm while the machines is relatively idle.
 

myuserid08

macrumors 6502
Mar 15, 2008
358
4
Do not open your mba and reapply the thermal paste, your warranty will be void.
I would start with an OS re-install and see if that solves the issue.
 

hellobenny

macrumors newbie
Original poster
Apr 26, 2008
19
0
I'd probably take it back but right now I'm in a country where theres no apple stores. Anyway, I think I will still try the thermal paste changing. I would try reformatting too but the license for coolbook I think can be activated only once, so if I reformat I'd have to buy it again.
 

hellobenny

macrumors newbie
Original poster
Apr 26, 2008
19
0
Yes I've checked that too, when I mean idle, I do mean the computer is pretty much sitting.

I've found that the fan does sometimes spin down, but it usually does so very gradually. My theory is that when I connect 1) the power charger and/or 2) an external monitor, it heats up the mba enough that even just sitting idle triggers the fans to rev up. I'm thinking that if I can reapply the thermal paste, maybe the idle temp will drop below enough so that sitting idle will not trigger the fans to rev up.
 

NC MacGuy

macrumors 603
Feb 9, 2005
6,233
0
The good side of the grass.
Yes I've checked that too, when I mean idle, I do mean the computer is pretty much sitting.

I've found that the fan does sometimes spin down, but it usually does so very gradually. My theory is that when I connect 1) the power charger and/or 2) an external monitor, it heats up the mba enough that even just sitting idle triggers the fans to rev up. I'm thinking that if I can reapply the thermal paste, maybe the idle temp will drop below enough so that sitting idle will not trigger the fans to rev up.

I'm not sure about external monitor but just the power adapter shouldn't heat it up at idle enough to get fan up to max.

The Airs fan does take quite a while to spin down. Longer slow down intervals than other maclaps I've used.
 

Sesshi

macrumors G3
Jun 3, 2006
8,113
1
One Nation Under Gordon
There's lots of stuff that unexpectedly causes the CPU to go ape. .Mac curiously is one of them when it can't get a connection due to firewall issues, etc.

I haven't tried the Air with an external monitor admittedly, but definitely one of the problems with the Air is that the GPU/IGP cooling is definitely insufficient, which leads to the CPU being affected. Try it without the external and see if you still get the same problems.

The fan will spin down very gradually on the Air (and not by a hugely differently slower margin than other Apple portables I've used), but it snaps on at full blast when it's far too late in an inadequately cooled machine for even mild 'real work' - this is pretty typical behaviour on all Apple machines, and one of the reasons they suck.
 

aristobrat

macrumors G5
Oct 14, 2005
12,292
1,403
My theory is that when I connect 1) the power charger and/or 2) an external monitor, it heats up the mba enough that even just sitting idle triggers the fans to rev up.
I've had the same experience with 2), when I connect to an external 23" monitor (where the default resolution is 1900 x whatever).

On my Air, even though iStat showed the CPU was running cool, the fans were still flying at 6200rpm.

If I picked up the Air and felt underneath, it was still hot. My guess was that the GPU having to deal with the monitors default resolution was causing the heat.

Fortunately for me, my version of 'real work' doesn't snap the fans on full blast, and I rarely use an external monitor, so I'm still loving my MBA. If I had to use it every day on an external monitor that caused the fans to run at 6200rpm, I'd probably feel different. :(
 

hellobenny

macrumors newbie
Original poster
Apr 26, 2008
19
0
I was just doing a presentation with my mba hooked up and the fans stayed at 2500rpm. The projector was only running via vga cable with 800x600 res though, so I'm guessing that is not taxing enough to bring up the temp that much.

Btw, I reapplied my thermal paste and I think this helped a bit, my fans seem to spin down after I disconnect the monitor. I am pretty sure that the plugging in the power charger does raise the temp though, I can see it right away while looking at istatpro (also the right side by the charger gets warm). I think this is to be expected from macs though, my old macbook pro was much worse in this respect, so I can deal with it.

One thing I did realize though is that I'd be much better hooking up my 24" to a nice desktop machine, so I could just keep letter my mba do what its best at, being portable. (I will probably build a hackintosh in the coming months)
 
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