|
This sounds a LOT like the loss of the video bias voltage to the collectors of the V-out transistors on the CRT board(possible one or three IC'S istead). This is around 200 volts, sometimes as high as 250, sometimes as low as 170. it almostr ALWAYS comes from the flyback--through a rectifier and cap.
Thee is a resistor in line with the diode from1 ohm to 10 ohms usually.. and it sometimes OPENS, sometimes due to a shorted diode. . As a result...the cathode does NOT get its "positive bias" and tends to float towards ground through the driver. This results in excessive broght ness and weak, often negative video.
|