Green picture tv bright green my tv works fine its a rca the sound works just the picture is green

A green screen on power up with retrace lines. At shut down a point appears in the middle of the screen. Sounds like either a shorted G2 grid, or bad flyback. If a phospher flake has shorted the grid in the tube, you can sometimes have luck by using a megger set at 1000VDC, to burn away the short. This is usually caused by the line HV going too high causing the anti-UV protection to kick in so fit a dummy load 40W lamp instead to the line output to allow measurements to be made.