[Elecraft] No bar graph on XV50

[Gilbert J Cross]

        Hi all, have just put up my 6 mtr. beam and have been listening
on 6 but not hearing any sigs yet.        
        Have noticed that I can not get the XV50 to go to bar graph
display when transmitting. Continues to remain in dot mode. Could be a
bad U4 or perhaps some other malfunction. 
        The K2 is functioning in bar graph mode.
        Any ideas?

                Thanks   Gil   K8EAG