01-31-2015, 11:14 PM
Had a similar problem on my 42-355, only to find a small dust bunny had made its home in part of the tuning capacitor. Once I took some compressed air and blew it out, the missing half of the dial returned. Can't say that it is something that simple causing the trouble on your 38-116. Of course my set has no back, which just invites dust inside. Not sure if your console has a back or not. Otherwise, yep, time to try different tubes.
Greg V.
West Bend, WI
Member WARCI.org