I am sharing this in case anyone else runs into a similar situation.
I bought a used, non working performance machine that would not home/center. When powered on, the carriage arm would move forward, but the printhead would just move in small jerks and never got to the center position. When I positioned the printhead precisely under the lid camera before powering on, it would occasionally complete the homing/centering/scanning process. When it did so, the printhead would move to the furthest right position and the interface would show “ready”. When it tried to print something, the printhead would move all over the place, the laser would fire, and when done the carriage arm would move to the back but the printhead ended up in to the right or in the center. The software had no idea where the printhead was located. The picture below shows the result of trying to score a circle.
I installed a new cable for the x axis stepper motor and all is well with the machine.
