[Jukebox-list] Help with Seeburg KD200

Hello, I have a Seeburg KD200 which I have enjoyed for many years - recently the mechanism travels back and forth continuously and the keyboard is not active, ie. No sound of relays when a selection is made. I checked the voltage at the Tormat Electronic Unit (Type TEU-1) to be OK at -300V. The fault may be around the 'Write-In' circuits but I need some help in the diagnosis. I have a service manual. I will appreciate any suggestions. Regards Rod George Australia.