CPU fan full speed showing 0rpm
a couple of days ago I tried to change my Seagate hard drive for another Seagate but with 3Tb and also install a SSD drive in place of the optical drive.
I thought everything went quite well during the installation but when I finished it turned out that the CPU fan was going crazy. I checked several posts and seen that other people complained about fans going crazy and it was due to some sensor not working, so I tried several things but none of them with result:
- Connect the optical drive sensor to the LCD sensor socket to see if that was the problem.
- Connect the optical drive sensor to the HDD sensor socket.
- Same as before but also connecting HDD sensor to LCD sensor socket.
None of them seemed to work so I ran AHT and I got this results:
- 4MOT/4/40000003 HDD-1416
- 4MOT/4/40000003 HDD-1422
- 4MOT/4/40000003 HDD-1426
So I thought that it was worth checking if all fans and connectors were working. I first unplugged the ODD fan and connect it to the HDD fan and it worked fine, did the same connecting it to the CPU fan and seemed to go like crazy, but worked.
Finally I decided to unmount the HDD fan and plugged it to the ODD connector and surprisingly it worked.
Then I tried to limit the fan max speed via programs like SMCFanControl or SSDFanControl but with no luck, all of them reported that the CPU fan speed was 0rpm and it's the one going crazy.
So.. my problem I'm totally lost. I don't know if it's worth buying a new HDD fan and see if it might solve my problem or if I might take the same route as others and hack the CPU fan, or maybe change the logic board...