Control Panel help/ Service Manual?

The Arjo Opera (now called the Maxi Move) I am working on will work only with the remote handset. The lift mounted control panel appears to be locked out or disconnected as the lift does not respond to any of the 4 button controls on it. I cannot find a service manual for it with which to explore if there is a way the control can be locked out or easily disconnected, It seems unlikely that all 4 buttons would fail at once. As the lift is currently located in a residence I want to minimize my time working on it and am looking for advice and or a service manual. ThanksSHAREit