Need to put the bulb parallel the B+ test point
if the voltage drops to the run voltage or adjust.
You need to move to the Horizontal section.
If so then you need to check for voltage on the collector of the Horizontal
driver transistor if low check the Horizontal drive transformer for a open winding.
Or bad connection in the area.
A combination of the two circuits with no load will make the B+ close to what it is
on the primary side of SMPS, having no regulation for the B+.
Check it out.