Some times error 341/048 occurs, checksum test for spotfilm device fails.

Hello, dear group. I need help for solving some problems in an Iconos R200 system. Some times error 341/048 appears during a cassette loading cycle. I check the tension of the cassette transportation belt, it is ok. On service mode, checksum test for spotfilm device fails to run, following message is displayed: "Timeout. No response to the stop request". On movements test for spotfilm device with service buttons, they function in reverse, that is, switch S1 opens the cassette tensioning arms, while switch S2 closes them. In the same way, switch S1 moves the cassette drive to parking position, while switch S2 moves it to loading position...and so on, S1 moves the anti-scatter grid to parking position, while S2 moves it to exposure position. As you can see, every movement control works in reverse. Could anyone give a hint to solve this problem? Any help will be highly appreciated. Thanks in advance. My e-mail: vicmaal@yahoo.com.mx