Zenith system 3 1979 repair help

[zeno]

Sounds like you may have a 1st gen System 3 If so it will have
a big power transformer. It was the most reliable color Zenith
ever built & had a great pix.
In any case pull the HV board either a 9-160 or 9-154 ( IIRC ).
go over it for cold joints & check the hoz yoke plug for burning.
If no joy there we will need to know what chassis it is.
Good luck

73 Zeno
LFOD !