Fan is going berserk!
Yesterday I baked a GPU on an iMac (27" mid 2011).
After assembling all together again, it works as is should except – The CPU fan is going berserk!
I have downloaded Macs Fan Control, and I have put the fan to "sensor based", and thus it behaves, but I would like for it to behave without this software. Something is obviuosly wrong.
I should also mention that the fan starts to max out as soon as I power it on.
My guess is that I have forgotten a cable connection when I assembled it, the problem is which one?
My question is: Where can I find out which cables go where? I have googled for this, but can't find any descent pics.
Help would be appreciated.
Thanks for the input! 👍
I just removed the display to see if I could see any missing cables. I have two empy ports, but according to internet these should be empty, AFAIK (see red arrows on attachment).
However, I realize that I might have reinserted the SATA cables from the drive and the Optical unit in wrong ports. Apparently there are different ports doing different things. These are located on the backside of the board though, so I want to be sure that is the error before disassembly. What should go where?
I should also mention that I upgraded this iMac with an SSD last year. At that time I installed SSD Fan Control and it has worked flawlessly until now. If I open SSD Fan Control now it only sees two fans.
Furthermore, the fans starts to max out not directly after restart as I thought, but when the login dialogue is present.
Cette question est-elle utile ?
Andreas - Any luck getting the diagnostics or get the TG-Pro output so we can discover why SMC is pushing the fans.
Alright, I have messed a lot with the machine, here's an update since last post:
- I took the time and disassembled the motherboard just to verify all connections, but all cables was in the correct place.
- I don't have the diagnostic DVD.
- Starting up with D took extremely long time. After 30 minutes of "Starting up from internet recovery" I aborted.
- No extra thermal paste but the factory applied one.
- I tried TG-Pro, but I couldn't change the rpm on the fans in any way. It showed the correct data though? Since this is a friends iMac I never bothered to buy a license.
- The only app that actually seems to regulate the fans correctly is Macs Fans Control (https://crystalidea.com/macs-fan-control...). The app have a setting called "Sensor Based" where you can set which sensor temperature, or an average temperature from all sensors, that you base the fan speed on. This setting didn't work with TG-Pro buy some reason. (I have some screen shots, but I can't find any way to add them in this post.)
par Andreas Carlsson
This tells me that the sensor actually work as they should, but something is effed up with the SMC communication. Maybe something got broken in the baking process...?
The machine works as it should, and with the app Macs Fans Control the fans behave as they should. My friend is happy, and with a little bit of luck she can use the machine one or two more years.
We will probably never know what's actually broken with this machine.
Thank you guys for the help!
par Andreas Carlsson