Chosen Solution
Internet research suggests that thermal paste an issue in old Macs. The ifixit guide for this model suggests a high level of difficulty, while redditors suggest that it not hard at all. Should I just return the SSD/RAM and sell it off with the original optical drive/HDD or is it worth trying to do it? if I’ve managed to do this, the next bit is just a matter of motor skills and following instructions? Will one of those stores that fix electronics be able to do it or is that too expensive to be worth it?
I’m suspecting your real issue is your HD SATA cable! Your Hard Drive Cable Is A Ticking Time Bomb and/or your cable is an older SATA II (3.0 Gb/s) version which this series had at the start and then Apple upgraded it and the drive to SATA III (6.0 Gb/s). Many heat issues like yours is due to your system having to work harder because the cable is worn-out or the older version. Here’s the needed part: MacBook Pro 13" Unibody (Mid 2012) Hard Drive Cable and the guide to put it in MacBook Pro 13" Unibody Mid 2012 Hard Drive Cable Replacement Also make sure you clean the dust build top on the fans and heat sink fins and maybe you should install a good thermal monitoring app like TG Pro
