Geoff ten Oever

HI I have a ML320 CDI 2008 , last week I manuall folded / pushed the drrver side wing mirror housing in to get past my car, and shortly afterwards I pushed it back to normal position , from then onwards the up down left right does NOT work any more, Strange but the fold IN/OUT function still works perfectly.I had a autoelectrician take a quick look today and he said that he THINKS its the mirror mortor thats faulty , BUT I find it hard to believe that the motor is faulty , IT doesnt make any noise when pushing the left right updown button , *** Can ANYBODY please offer any advice on how I can sort this out ,