No vertical deflection
Check or change R312, 2.2 ohm 2 watt, Ic301 and R317 1 ohm .5watt
and R855 off fly lift one end of resistor and measure the ohms?
confirm C306, C308, C314 and C466,C847 have been replaced.
The resistor's don't fail everytime,just check if they are open.
The Ic and caps need to replaced each time one or the other gets replaced.
Let us know.