You can start with getting a terminal output. Use the search function in the forum with keywords like "Seagate serial adapter", etc.

Multimeter use is to run tests on the PCB should it be faulty. But what is the point if the PCB is working fine?

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Hard Disk Drive, SSD, USB Drive and RAID Data Recovery Specialist in Massachusetts

No, unfortunately there isn't
Everything points to internal failure, which unfortunately not the answer you expected, and its not a DIY

Warning, the following advice can make things worse.
So, I repeat, if data is valuable to you, "stop playing with the drive and send it to a DR pro"
But if you insist, buy a TTL cable and start playing

THANKS. I have taken the advice and purchased a TTL. I have searched and will continue to research the forum. Just a bit of info. I have accessed the drive via terminal and have come to the conclusion that the PRE AMP TYPE of my original drive is different than the donor pre amp type. Not sure if this makes a difference but my next step is to try and find a donor with the same pre amp as the original.
Thank you.