Dark & no focus point to the HV divider which is almost always
built into the FBT ( flyback) as the focus & screen controls.
Normally I would measure the G-2 pin of CRT BUT there is
a chance of too much voltage that can wreck your meter.
Check for cold solder joints under the FBT first. Usually a pin
set apart from the rest & flat. To track down the noise you can
use a stethoscope made of an old paper towel tube. Odds are
the noise is coming from the FBT.
73 Zeno
LFOD !