[drh4683]

Yes, check the focus pin at the CRT. Ive noticed many zeniths will focus at one end of the control, but you think it could be even better but run out of adjustment. Sometimes, like in your case, its still unacceptable focus at one end. Proper focus should be obtained near mid rotation of the control. Im many of those cases, I've replaced the focus rectifier diode and it does fix it almost every time. You can't really get an accurate test on a selenium focus diode with your meter as they have very high forward bias resistance. Your best bet is to sub in a new one and it will probably bring back a picture that will blow you away. Its amazing how good the picture is after I put in a new diode. Even if you had a decent picture as it is that you were comfortable with, just putting in a new diode makes it razor sharp! You set has a 23XC38Z chassis, and there should be a 212-48 rectifier diode on the flyback PC board. You can get an NTE-118 but they are rather difficult to find as NTE no longer makes them. Its a selenium diode, Im sure moyers has them though. They might even have the 212-48, but doubt it. Moyer comes up short on NOS zenith parts as they were not a zenith parts distributor.