Chosen Solution
Hi there. In January I purchased a new Mid-2012 MacBook Pro. It has been working great, up until a few days ago when I updated to MacOS Catalina 10.15.4 . Since then, it has just been going incredibly slow, and every single click seems to bring up the rainbow swirly thing. I need my laptop for school, and I have ran First Aid on Disk Utility, but that did not say that anything was wrong with my drive. Can anybody please help me? Thank you so much.
I’m suspecting your drive is having problems. There are a quite a few things here that can do you in. The first is the HD SATA cable tends to get worn causing errors as the insulation was bit thin on some cables. The second issue is the original cable was not rated to support SATA III (6.0 Gb/s) data rate. The original HD’s Apple used never pushed the past the limits of SATA II (3.0 Gb/s). High RPM HDD’s or SSD’s can push hard on the connection so having a poor quality cable will show its warts! So you;’ll need to replace the cable MacBook Pro 13" Unibody (Mid 2012) Hard Drive Cable and to help protect it you’ll want to place a strip of electricians tape on the uppercase where the cable crosses over Your Hard Drive Cable Is A Ticking Time Bomb We now come to the install part of the cable here’s the guide you’ll need to follow MacBook Pro 13" Unibody Mid 2012 Hard Drive Cable Replacement But you need to be careful as most people damage the cable by mishandling it. The cable needs a few bends, so people just assume you can create it and all is well. Sorry No! That only damages it! You need to find an old BIC pen ink straw to use as a forming brake as we want a nice arc no sharp bends! Using the Ink straw to help you form the radius will safe you hours of struggle later on! Now the fun part after replacing the cable you’ll want to make a fresh backup as the structure on the drive is likely corrupted! Once you’ve got a good backup format the drive and install a fresh copy of macOS. I do strongly recommend you stick with Sierra as being the best for your generation of MacBook Pro. SATA based systems work better with the older HFS+ file system (HDD or SSD) if you have a real need bypass High Sierra and stick with Mojave, Catalina has too many problems I would stay way from it.
