Chosen Solution
Last week while I was watching Netflix, the streaming got suddenly interrupted. In the beginning, I thought that was my Internet connection, but then I discovered that the computer slowed down to the point of being not usable at all. If I tried to scroll down a page I was able to do it for max 2 or 3 seconds and then I have to wait around 30s to 1 min to continue. So, I concluded that my SSD drive (OWC Mercury Extreme) was broken. I performed several tests: First I used the Target Disk Mode and used a FireWire 800 cable to connect the computer to my old MacBook Pro. I tested the disk with Disk Utility and showed no errors. I then restarted the computer in Diagnose Mode and showed something that I know: the battery is old and I must change it. But, nothing else related to SSD or memory. Then I booted the old mac using this *MacBook Pro 13" Unibody Mid 2012 2.5 GHz in Target Disk Mode using the FireWire cable and it worked perfectly!!!! So, the SSD seemed to work right with the other computer. I removed then the SSD and installed it in an external case. Then I used this to boot the old computer. Perfect. I installed the old mechanical disk, then used carbon copy to clone the SSD… and guess what. With the old mechanical disk, the computer works fine. So I erased the SSD, cloned the info again, installed SSD internally again…. And same behavior… Extreme slow booting, Beach Ball of Death at login screen with 2 or 3 characters of my password… Useless. I downloaded Catalina as recovery and the same behavior. The SSD only worked fine inside the computer in Target Disk Mode, or in the external case. So I guessed that maybe something in the SSD was defective but the different tests were unable to detect the fails and maybe the disk was unable to work internally. OR something was wrong with the computer per se. I decided to try with another SSD. I bought a Samsung EVO 860 1 TB Today I cloned the info. Installed the new SSD and guess what… Spinning beach ball of death. So now I now that my old SSD is fine and the problem is inside the computer. Currently, I am writing this post using the computer with the mechanical drive installed since I need to keep working, but I know that something is definitely wrong. From research, I read that maybe the HD SATA cable is gone bad. Then in this forum, I found a similar opinion in this post: SSD Unreadable after battery died.. Could it be that I have the same problem too? HEEELLLPPP PLEASE!!! Thank you very much in advance. Looking forward to hearing from your ideas. Pablo Update 1 As suggested, I downloaded the app CoconutBattery. Here is my current status, working with the battery. Please let me know if I should take more screenshots, for example, with the fully charged battery or with the computer connected to the power adapter. Thanks again!!!
Update 2 I tried the tape suggestion without any success. :(
I can´t scroll down. As you can see the SBBOD is lasting more than 30 secs, and I can scroll down only 5 or 6 sec. I use the scrolling as an example, but the computer is unusable in any case.
Update 3 Solved!!!!!. As suggest in SSD Unreadable after battery died.. I just replaced the HD SATA cable with a newer one. As an addition, I used Mayer suggestion to use tape on the bottom of the case to prevent the cable from touching the surface . Also I taped the area of the optical drive. Thanks a lot. My computer is now working. I will change the battery after I come from my vacation. Once again, thanks!!! Peace, Pablo
STOP CLONING! Cloning was great until the advent of the repair partition. With Cloning you do not get the partition. Best thing to do now-a-days is to format the drive (if using High Sierra or above the with be GUID APFS), install your system and then Migrate your APPs and data and user. The biggest problem this model had and still does is the unprotect hard drive I/R cable. For a while Apple was even replacing it for free.
As you may be able to see in this photo, there is electrical tape on the bottom of the case to prevent the cable from touching the surface of the case. Also on the optical drive you can see 3M Extreme mounting tape being used to prevent the bottom of the case from contacting the cable as it comes over the stair step. This is the location of the majority of the cable failures.
