No green color----all other colors seem fine and

The most likely cause is a bad (shorted or open) CRT driver transistor on the green CRT board. Also check the solder connections on the connector sockets for wires that get plugged into on the CRT boards (and check all the CRT boards; not just the green CRT Board).

The next most-likely cause is a bad green CRT. Try tapping (gently!) on the neck of the green CRT and see if you get any green flashing on the screen. If so, then you've got a bad green picture tube.

Note: I am assuming you are an electronic technician with at least basic knowledge of electronics, and that you know how to solder and test components like resistors, capacitors, diodes, and transistors. If not, you better defer this repair to someone more experienced.