You can put a request for the firmware in the Service Manual request forum and someone might offer to give it to you. I'm retired and no longer have...
I think I'd examine, and possibly clean the encoder strip. Ink on the encoder strip can cause this effect. A sticky carriage rail can also cause this...
Check that this old lady is setup to show jam code, should be in system 2 if I remember correctly.
Next is to put gate switch solenoid plate mode on...
LOL! I had the C13/NEMA 5-15 cable start to spark, then smoke, then shot out cool green flames from the side of the connector. To be perfectly honest...