Newbie question - MMF 5.1 channel cutting out

I just made the leap and swapped my old Technics for a new Musichall MMF 5.1. One of the channels keeps cutting out. I have switched left and right outputs/inputs from table, phonostage, preamp, and isolated problem to table. Took the table to the dealer who moved the wires around in the back of the tonearm which seemed to fix the problem. He said he has seen that in another MMF 5.1 as the one of the wires was touching a metallic part. This has happened once again when I brought the table home and managed to fix it by moving the wires around again. Is this normal? I am astounded that what I thought was a quality product is doing this. Appreciate your input.