Chosen Solution
I have a MacBook Pro unibody Mid 2012 13” I had installed an SSD into the Optical bay, everything was running fine for 2 years with this setup. It did not fall any physical attack… But nowadays I’m getting a strange error that my fan is running 100% and the system is very slow in (I tested both the HDD and SSD they tested good) CPU eaten by Kernel over 200% and then i did following test AHT successful no error in both extended and normal (no temperature sensor error) But, when it’s freezing or hanging I managed to open TG Pro and it shows: GPU diode N/ACPU GFX N/ACPU 2 N/A It does show Temperature sensor error: HDD sensor (but even when I disconnected HDD in main bay and booted from SSD from optical drive). But, the amazing thing is, that now when I restart after the hanging boot up and then ran AHT it shows success and then everything runs fine and with full speed. Now it’s giving random errors, I cleaned my logic board, applied new thermal paste as well, still no success. What is the problem? Is my logic board about to die? Or, I do I need to re-ball my intel 4000 chip or HDD temperature sensor failure? Update (11/08/2018)
the gpu is showing 129 C ,TG pro was not accurate @benjamen50 can you please check ,should i be reballing my gpu or some other sensor
Does sound like a HDD temperature sensor issue, does the application HWSensors show Hard drive temperature sensor with the same problem? Seeing how the sensor is located on the hard drive cable I recommend starting with replacing that. MacBook Pro 13" Unibody Mid 2012 Hard Drive Cable Replacement MacBook Pro 13" Unibody (Mid 2012) Hard Drive Cable
