We have a carwash automatic controller board with an Eagle Signal Micro 190 PLC. The program has been reloaded after power outages from a MX207l1 EEPROM Memory Transport Module for over 20 years. Suddenly the reload isn't working -- either the MTM lost it's program or the socket has worn out over the years. Anyway, the program can also be loaded via a 9-pin serial cable from a PC. In trying that, we've found that the program the vendor gave us on the PC doesn't match that on the MTM. Testing shows that only one output is incorrect. We simply need to change output on O22 (broken trace on the board 20 years ago) to O20 (which would then match the MTM code). I am a software engineer, but have never used ladder logic in a PLC. I *think* I have changed the output, but maybe I just changed a comment. [Testing requires powering off the carwash, with loss of $$ if we can't get it back up, and $80K expense for total failure, so trial-n-error isn't feasible.] (1) Can anyone discuss what I did with me so I have a better idea if it will work or not? (2) Is there anyone in the Atlanta area willing to look at this? Thanks for reading!