Focus voltage is to low. IIRC should be abt 5KV.
Measure at the yellow wire. Should be abt 6 KV IIRC.
If not lift the yellow wire & see if it comes up. If not its the stick or the green
3W resistor.
2) lift the black wire to the CRT socket. At the focus control
center pin you should get 4-6 KV at the center pin. If so suspect the CRT
socket. Voltage will be dependant on the control setting.
Hope I got that straight, been a long day !
Just remember its a simple voltage divider....
73 Zeno
LFOD !