Arnie

Today I suddenly gut this button assignment problem with my MZ-RH910. After a mechanical shock the buttons (on the MiniDisc player as well as with remote control) have wrong functionalities. So the FF button now has REW function and the REW button has T-MARK function. This is quite a problem. I manage to enter service mode and i also can use the KEY CHECK MODE there, which confirms the wrong functionalities. Does anyone know how to fix this problem? Is there any setting in service mode to do this? Is a reset in service mode an option (what exactly does it?)? please help me