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Dr Kevorkian94

macrumors 68020
Original poster
Jun 9, 2009
2,179
83
SI, NY
Hey guys, my fans on my iMac are running very fast and continually. The mac is cool to the touch and I've tried reseting the SMC settings to no avail. There was no problem like this until I picked up my iMac from my local Apple Store. I had a CD stuck in the optical drive so i just had the Apple store take it out for me. There is a good chance this is related but I'm not sure how. Also my CPU activity is normal. Thanks for the help!
 
...There was no problem like this until I picked up my iMac from my local Apple Store. I had a CD stuck in the optical drive so i just had the Apple store take it out for me. There is a good chance this is related but I'm not sure how ...

The Apple store would have removed the optical drive to get a stuck CD out of the drive - the drive cover has to be opened up, and you have to remove the drive to do that.
There's a temp sensor on the optical drive that plugs in to the logic board. I suspect the shop left that sensor disconnected (your fan will run at full speed when the temp sensor is not connected) I THINK that if the optical temp sensor is not attached, then only the optical drive fan will run top speed, so a utility that shows the fan speeds will also pin that down. I could be wrong, and all the fans run.
Anyway - take your iMac back to your friendly local Apple shop. They'll fix you up.
 
See I though this as well, but I thought maybe there could be another explanation. Anyway I booked an appointment at my apple store. Thanks!
 
Definitely a disconnected sensor cable. I've opened my machine many a time and forgotten to put them back and come across this.

BTW if you're being charged by Apple for these repairs (which I assume you are with it being an old machine). I'd highly recommend learning how to open and fix it yourself. The 2008 models are really easy to open with few tools (you will need a suction cup) and they're easy to maintain and clean once you know what you're doing.
 
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Definitely a disconnected fan cable. ….

Eh, could be fan, but more likely a temp sensor from the optical drive. That gets disconnected. Either way, Apple needs to set it right. It's entirely possible, too, that a plug or cable was damaged (it happens :D ), and, even though it's easy to get access inside, the Apple repair likely should be fixing that.
 
Definitely a disconnected fan cable. I've opened my machine many a time and forgotten to put them back and come across this.

BTW if you're being charged by Apple for these repairs (which I assume you are with it being an old machine). I'd highly recommend learning how to open and fix it yourself. The 2008 models are really easy to open with few tools (you will need a suction cup) and they're easy to maintain and clean once you know what you're doing.

Well I dident have the drive fixed because I never use it (except for this one occasion where I could of just downloaded the drivers....it was my own laziness that got me). Not only that but I'll be giving it to my younger brother and getting the newer model with the drive sold separately. Since the Apple drive is $79 and the repair was $150 I just asked if they'd take the disc out for me (it would randomly start reading it in the night and wake the Mac up). So I didn't get charged but you bring up a fair point,I'll look into it. Whatever the case is I have a appointment on Wed so I'll report back with wahtever the problem actualy was.
 
Eh, could be fan, but more likely a temp sensor from the optical drive. That gets disconnected. Either way, Apple needs to set it right. It's entirely possible, too, that a plug or cable was damaged (it happens :D ), and, even though it's easy to get access inside, the Apple repair likely should be fixing that.

Sorry that was a typo on my part, I did mean temp sensor cable.
 
It could also be the LCD temp sensor. To get to the optical drive on that iMac, you must remove the LCD and to remove the LCD you must disconnect the LCD temp sensor.
 
It could also be the LCD temp sensor. To get to the optical drive on that iMac, you must remove the LCD and to remove the LCD you must disconnect the LCD temp sensor.

Or the HDD sensor. Easiest way to find out is to install iStatPro in the dashboard, you'll soon see what's missing. I can't remember if it'll show a temp reading of 0 or just nothing at all.

I know that the machine won't boot with one of the temp sensor cables disconnected but I can't remember which one. Think it might be the screen actually.
 
Removal of the HDD and/or HDD sensor is not required to remove the optical drive.

It's not but to be fair we have no idea what the folks at Apple have done inside the machine or what their procedure is. We've seen on these forums that they've done some odd things over the years just to try and fix something simple or obvious.

For all we know they could have unplugged everything upon disassembly. Stranger things have happened.
 
Proper AASP for this is: Remove memory access door, front glass, remove aluminum bezel, remove LCD screen, remove optical drive, disassemble or replace optical drive. That's what the Apple Store followed unless the tech there is lazy or wasn't follow their directions.
 
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