Chosen Solution
== Ok so I have a a1278 MacBook Pro and the fan Is spinning at full speed. But it’s showing 0 rpm in macs fan control. And all,of the temperature sensors are fine. And i’ve done a smc reset and pram reset but nothing worked. I also replaced the fan that didn’t work either. So i’m pretty stumped right now
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UPDATE 3/27/2019 I found the cause the fan spinning at full speed. The fan connector on the motherboard was loose so it may have not contacted the data pins. So I got cardboard cut it with an X-Acto knife and a small command strip that was cut then put it on top of the fan connector so it would wedge against the bottom metal plate. And it worked! Thanks for the tips though
So we can see the thermal sensors are all working correctly which is a good sign! You still could have one of the other SMC sensors on the logic board failing. Clearly the fan is not reporting its RPM so I’m suspecting the tach unit within the fan has failed. You might want to run diagnostics to see if any errors pop. Restart the system and press the D key. Did you get any error messages? At this point I would replace the fan unit MacBook Pro 13" Unibody and MacBook 13" Unibody Fan to see if that solved the issue. If not the logic board fan control logic is damaged.
