I won't give you software that has a potential for an accident or getting someone hurt. You being a board repair facility should have an EPROM programmer and if you can read the chips, software is usually not the problem. A bad TMS 600 power supply can also cause the problem.
I checked the power part, it has no problem.
The software read by the programmer seemed corrupted in some parts of it(need to confirm that), that's why i needed to check from a healthy one.
I also tried the removable chips in another board and gave me the same result.
So the problem is most likely related to the software.
However, I understand your desire to provide the 100% correct software and i appreciate that, so i will wait for the reply from the guys running the whole system about the speed and the specification of the Elevator.