The robot is now fixed.
The computer had an intermittent problem. I found another CP01 computer on fleebay and it has been running perfectly for weeks.
In retrospect the faulty computer was creating alarms that pointed to issues inside and outside the computer. The Motoman diagnostic documentation said if the problem is not with the component specified in the particular alarm, you should suspect the computer itself.
The help desk at Motoman service was instrumental in solving the problem and guiding me through the entire process. They supplied me with all the information I needed to swat out the computer.
My thanks go out to Motoman service and Robodoc and everybody here on this forum!
Cheers