Check the DC voltage at the positive of the cap. Should be 200-225 VDC.
The lower it is the brighter the pix will get. I will pull the manual
tomorrow, I should have it.
Also you can check the resistor packages on the 9-88-? and
the 9-121 CRT board for cold joints. Very common in the olden days.
They are the long flat B&W ceramic things.
73 Zeno
LFOD !