Avoid Zeniths after apx 1992 & "digital" processed sets
(marked Digital System 3 )
Avoid most Sonys apx 1974-1977 12" 17" 19" & 21"
Avoid RCA TX81, TX82, TX825 chassis
Panasonics are safe.
As a rule the easiest to deal with are solid state sets up to
the late 80's. Tube & hybrid sets tend to have multiple
problems.
73 Zeno