Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

ben2e

macrumors member
Original poster
Nov 26, 2007
64
1
2011 iMac 27"
Intel 510 SSD

My fans were going nuts. After fan control software failed to make any difference, I ran the hardware test and got the error above. Any idea how to figure out what I may have failed to plug back in ? (Or hopefully not broke on the MB ?). Before I reconnected everything I even tried disconnecting SSD and HD but same crazy fan action. I've read the guides and associated HDD fan issues but this issue seems to be with other fans.

Sorry if I've transposed Oh's and Zero's above. All three fans for me seem to be going ballistic, but iStat is reporting reasonable temps (which should be the case).
 
Last edited:
My fans were going nuts. After fan control software failed to make any difference, I ran the hardware test and got the error above. Any idea how to figure out what I may have failed to plug back in ? (Or hopefully not broke on the MB ?)

Sorry if I've transposed Oh's and Zero's above. All three fans for me seem to be going ballistic, but iStat is reporting reasonable temps (which should be the case).

You didn't state which iMac you have. If it's a 2011 model, then do a little reading here, and do a whole bunch of Googling and reading to learn about your 2011 iMac and it's HDD and SSD limitations.
 
I believe that TAOP mean the Ambient temp sensor is damaged/disconnected from logic board. You'll need to open it up and check to make sure that sensor wasn't damaged somehow and/or that you plugged it back it. I did this yesterday in my 2010 imac. I accidentally pinched the optical drive sensor which made the optical drive fan and the cpu fan rev up. I had to open it back up and tape the damaged areas. Good luck.
 
2011 iMac 27" 2.7GHz

I have read about the HDD sensor issues but mine seemed to be different. I believe most folks who did the SDD addition didn't have hardware failures, they just suffered from HDD fan issues which could be fixed by fan control software. That wasn't the case for me.
 
I believe that TAOP mean the Ambient temp sensor is damaged/disconnected from logic board. You'll need to open it up and check to make sure that sensor wasn't damaged somehow and/or that you plugged it back it. I did this yesterday in my 2010 imac. I accidentally pinched the optical drive sensor which made the optical drive fan and the cpu fan rev up. I had to open it back up and tape the damaged areas. Good luck.

Thanks. That seems worthwhile investigating. There was a bewildering number of connections to that MB. Seems like the optical drive sensor should be obvious enough. Whatever I can do to avoid pulling the MB again !
 
Thanks. That seems worthwhile investigating. There was a bewildering number of connections to that MB. Seems like the optical drive sensor should be obvious enough. Whatever I can do to avoid pulling the MB again !

Just be to clear, I believe your error code is referring to ambient temperature sensor.
 
Which one is the ambient sensor ? (location-wise inside the iMac)
 
Which one is the ambient sensor ? (location-wise inside the iMac)

OK, found it. Bottom left corner, right under the CPU fan.

Strange, I never touched the sensor itself and it was fairly well protected there under the CPU fan which never came out. I'll call Apple tomorrow and confirm that's what the error code means. It was definitely plugged in. Darn... Wishing I'd just paid up for the SDD from Apple at this point.
 
Apple Technical support couldn't tell me what the error message meant ! Granted I didn't get to 2nd or 3rd level, I was still surprised they had no access to a meaningful list of error codes. Time to take it to the Genius Bar.
 
iMac self service is ok until you make a small mistake and find yourself with a catastrophe. It's just too delicate for DIY upgrades.

I have to agree. I know people have done it successfully but these things aren't made to disassemble over and over. It creates wear and tear on the parts as well. At this point, if I'd paid myself $20/hr, I'm sure I haven't saved a dime.
 
I agree as well that it is generally not worth it doing yourself and things are going to become worn and/or break if you keep having to go in. I have probably removed the lcd 10-15 times and had to remove the logic board 3-4 times. Things that have become worn and/or broken since opening it:

1. One of the screws that holds the LCD to the case has become stripped and no longer screws tightly to the plastic part.
2. One of the plastic locking tabs on the display port connector broke the first time I opened it.
3. I damaged the optical drive temperature sensor by screwing the logic board on top of it.
4. A piece of metal tape which held one of the wires to the case came lose.

After finally getting my OWC SSD installed, I find out there is a problem with it freezing after sleeping so I have to remove the drive and send it back to OWC. I would recommend people paying an Apple Certified Tech to install it if they really want an SSD besides the Apple SSD.
 
Took it to the Genius bar and indeed this is the Ambient Sensor that failed. I'm still not sure why but it's in to the Genius Bar for repair.
 
What did they say about you installing your own SSD? Are you having to pay for the repair?
 
I won't find out for certain till I get it back but I did replace the original parts. I didn't like doing it but I didn't want to take the chance either. I'll be mighty relieved when this is all done and may not ever mod my iMac again.
 
Apple rocks ! They repaired it and claimed it was a bad main board. Strange that only the ambient sensor function would stop working but possibly the pins or socket somehow stopped working. These things are so small, not really meant for human fingers.
 
I just did the SSD upgrade in my 27" i7 and I am getting the exact same error. I really hope it's not the mainboard in my case. I will pull it apart again and make sure all the connections are good and that the ambient air temp sensor is hooked up and not pinched in any way.
 
Apple rocks ! They repaired it and claimed it was a bad main board. Strange that only the ambient sensor function would stop working but possibly the pins or socket somehow stopped working. These things are so small, not really meant for human fingers.

Hardware Error 4SNS/1/C0000008:TAOP--124 after SSD install

I have the same problem with you....
Finally, how do you resolve this problem?
Thanks for your help!!
 
Do you install SSD again!?
After U fix Ur iMac!?

I sure did. Was extremely careful the second time and fully removed the motherboard rather then just trying to lift it up a bit to plug in the sata cable. Works perfect now. Couldn't imagine my iMac without it.
 
I sure did. Was extremely careful the second time and fully removed the motherboard rather then just trying to lift it up a bit to plug in the sata cable. Works perfect now. Couldn't imagine my iMac without it.

Good job!
I think I will do it after I fix it
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.