1950s or '60s vintage Zenith TVs, Need some info

[zeno]

Run the set a few mn & see if the tubes get hot. Its pretty
rare on a parallel filament set to get an open tube never mind
two of them.

Next run set. Change channels. You should see & hear a lot of noise
from the switches making & braking.
If you dont its father down the line, prob one of the IF tubes.

73 Zeno
LFOD !