Its an EFL in line CRT.
Most common for the symptom is
1) loss of the 200V source for the 3 video outputs.
2) too much G-2 volts. Resistors in divider open.
3) cold joints on the 9-88 module resistor pac.
Cold joints on the CRT PCB also common. Resolder ALL of the film
pacs.
73 Zeno
LFOD !