Thin vertical line on plasma, 4 inches from left hand side

How old is this TV set? If it is less then a year, call an authorized Hitachi repair center. Your problem could be a Display driver board, or possibly the plasma panel itself. There is a slight possibility that the digital board could have a fault in it as well, but highly unlikely. On sets like this, this is why you want to call out an Authorized repair center, as they have replacement boards to check. If you buy a board, and it turns out not to be that board, you are stuck with it. If the panel is bad, you will probably buy a new set, as the cost of the plasma panel is more then the entire TV set. It is impossible to diagnose a TV set like this without the boards. Good Luck

According to what i could find, there is no way to actually SOLVE the problem, this is what i did find; The plasma display panel is lighting the phosphors by the discharge of internal radiation. Depending on the screen contents, in rare cases this may cause vertical stripes to appear because of failure to light. Please note that this is not a malfunction.