NSM PRESTIGE 120C

Hello,
I have the following problem with my NSM Prestige 120c.
The relais of the selectionbuttons won't be activated.
I can´t make any selection.
When I start the jukebox, he everytime takes the same single over and over again untill I interrupt. The slide won't move over to another place.
Can somebody help me or give me advice about my problems.
Thanks and I hope someone will respond