Be sure the cap is where the old can is. Once I had a similar age 19"
Zenith & just changed the bad section due to the age of the set.
I mounted the new one away from the can in a nice big open spot.
After that the vert blinked sweep/ no sweep / sweep etc rapidly.
D-labs on U tube has a nice can replacement technique using an
octal tube socket. See his videos.
73 Zeno
LFOD !