Elliot,
Easy to get to, you remove the power supply cover front plastic (where the power cord is) there are two side screws also that holds the cover then a few small screws at the top edge. Behind that is the input board held in place by a few machine screws. Unplug the connections and remove the board. Usually you will find a broken solder joint from shipping or impact. Also check that its not the cable connector itself. Doug
Easy to get to, you remove the power supply cover front plastic (where the power cord is) there are two side screws also that holds the cover then a few small screws at the top edge. Behind that is the input board held in place by a few machine screws. Unplug the connections and remove the board. Usually you will find a broken solder joint from shipping or impact. Also check that its not the cable connector itself. Doug