Tatung VS14228T retrace lines

[badbaud]

This is the one that has the power supply located inside a metal cage which is mounted above the board and the neck board has transistors but no IC.

Did a complete cap job, all electrolytics replaced.

Replaced H and V transistors on input.

Replaced vertical amp and H/V IC.

Still get retrace lined from the middle of the screen to the top of the screen.

All I have is a blurry schematic to work with and can't figure out how blanking is developed in the circuit.

Any help would be appreciated.

[montech]

Check R720 off pin 10 and 12 0f the LA7837. Its a weird value like 140 ohms at 2 watts, I have seen them go way up and cause this problem.

[badbaud]

Thanks! I'll give that a try and let you know.