Fan Replacement

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Level 2

205 points

Fan Replacement

Hello All,

I purchased this iMac in Feb 05 and no longer qualify for chat. My fans were screaming after about 2 months so I returned the computer for repair. They checked the machine and said it was operating within parameters albeit a little loudly, but they would change the fans if wanted. They said they had to order the parts and told me they would call me when the parts arrived. (Its about 85 miles to the store). They called about 2 weeks later and asked me to bring in the machine. I dropped it off and they handed me the work order they ordered 3 fans for a "Rev B iMac ALS". Mine is a Rev A. They kept the machine for 1 day and said they replaced just the lower fan (CPU fan on the 17" iMac). The machine was just as loud the day I picked it up as it was when I dropped it off. I thought it must be operating normally and have tried to live with it. I just turn up itunes a little louder, but I cant anymore. Sitting idle I can hear the machine running at the end of the hallway 40' away. So I will turn it in again to hopefully repair the fans.

My question is this since it was just as loud after as before:

Can they replace the CPU fan (lower on the 17") without replacing the midplane?

or Are they trying to placate me by telling me they replaced the fans.

Also My HD temp is always 130-131 and the fan never changes its 2000 RPM even when the cpu fan is at 5200+. is this normal or should I worry about this.

Thanks for the info

Tim

Posted on Oct 8, 2005 8:38 PM

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Answer 1

Oct 8, 2005 9:16 PM in response to 2T

It is possible that the fans in your imac are working properly. If they are running faster than usual, it means that there is a problem somewhere else. Fan speed is not controlled by the fans; these speed up/down depending on the voltage being sent to each.

Download "Hardware Monitor" (it costs around $10.00), and see how fast the fans are running, and the voltage being sent to each fan. Also, take note of how hot the hard drive and the CPU are.
----

At the moment Hardware Monitor indicates that the CPU in my iMac is running at 138 degrees, and:

Hard drive = 126 degrees
Hard drive fan = 2000 RPM

CPU fan = 1666 RPM
System fan = 1500 RPM

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Answer 2

Oct 9, 2005 4:12 AM in response to 2T

2T, HD temp is fine. I have the same unit and noise isn't an issue. Down load X Resource Graph http://www.gauchosoft.com/xrg/ and check what your cpu and mem usage is. Run Activity Monitor (MAC HD-Applications utilities) and see what apps you have running. Some apps run in the back ground and hog memory the bring back some more info.

Dick

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Answer 3

Oct 9, 2005 6:25 AM in response to 2T

2T:

The CPU fan can be replaced without replacing the midplane. In fact all of the fans can be replaced without replacing the midplane but Apple argues and may still do that the midplane has to be changed to change the other fans. That may be the case if the fans run at a high speed but not making any unusual noises. As mentioned before, if there running at high speeds, it may be do to some other program running or something wrong with the signal the fan(s) are getting and that may be a midplane problem. If the fans are running at acceptable speed but making noises other than movement of air then it may be just the fan and that can be changed without changing the midplane. Even in version A, for the 20" model, the two to fans can be changed without changing the midplane. But Apple insisted, at that time, and may still insist that the midplane has to be changed in order to change the fans.
Are they placating you? I don't know but they would be stupid to pull such a trick. In your case, it may be the midplane. A fan doesn't go off on its own. It gets a message from somewhere(midplane). But check to see if another program is operating. If you are within one year of purchase, I strongly suggest you get the two year extended warrenty. It is worth it. But don't give up although it is something that you or anyone else should not have to.

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Answer 4

2T Author

Level 2

205 points

Oct 9, 2005 12:19 PM in response to 2T

Thanks Guys for the info.

The only program that is running is Safari and X Resource while posting on this board. I have even disabled Dashboard I cannot run more than one or two programs at a time. It sounds like there is a model plane inside my iMac. The sound threshold is somewhere around 2000 RPM on the CPU Fan when the noise starts. The hard drive never changes it seems as if this fan is a constant speed not a variable speed fan which is why I was wondering. This computer makes enough noise that if I try encoding video I have to leave the room and close the door. As for games Halo sends the fans screaming at 5300+ RPM.

Again Thanks for the info. I guess my only option is to take it to the Apple store again.

Tim

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Answer 5

Oct 9, 2005 5:13 PM in response to 2T

Did the fan noise increase after upgrading to Tiger?

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Answer 6

2T Author

Level 2

205 points

Oct 9, 2005 9:12 PM in response to Doc Spider

Doc

No Its been like this since a few weeks after I purchased the machine. I have had it in once already for the CPU fan replacement. I think that was in July I'm pretty sure I was on 10.3.9 when I turned it in the first time.

Tim

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