First try unplugging the set from the mains for about a minute to let
it reset. If this does not help, it is possible that there has been
some damage to the controler area, or the EPROM information has some
damage. If this is the case, you will have to take the set to a tech
who is set up to be able to reprogram the EPROM if need be, also to
troubleshoot the set.

Jerry G.