Zenith roundie centering

[reeferman]

Wow,

You say neither of the strings respond??

The strings (one for horiz and a separate one for vert) are each set as a loop, pulling on one side of the loop or the other should make the adjustment. I've seen people take the horiz loop in one hand and the vert loop in the other and pull on both to try to adjust them that way (which won't work).

In all my experience I think I only had 1 that didn't respond. File 13 time.

You may start looking for a replacement

In the meantime, fiddle with the height and linearity adjustments. If they don't work, got out the scope.

The resistors very much go bad in the focus circuit. However, check for corona on the tube socket. Check in a very dark room.