Autotrail media centre

[critch]

Hi All just got back from Spain great time apart from juddering step, another problem which some of you may be able to help with is that our MH has the famous reliable Autotrail Media Centre , 2013 version fitted, and on this trip the speakers stopped working, I gave the right hand door pillar a thump, and sound now comes but only on the driver's side, as my wife is a touch deaf this caused a few problems any help appreciated.