Brightness control circuit, the brightness degree of faults can make the grating light brightness, the image is grey, but will not result in a color image. Image too bright, flyback line, fault should occur in partial color depending on the level at the end of the circuit and kinescope. As an cathode and filament tube, causing the electron beam current is too large, out of control; And as apparent breakdown or short circuit at the end of the pipe, make the picture tube cathode potential drop too much, electron beam is out of control. When the base of color slants a color, such as partial red, green, blue, three colors, should check the corresponding mainly depending on the circuit and the tube at the end of the cathode potential. If yellow, green, purple, should check at the end of the corresponding view of its complementary color mainly circuit and kinescope cathode potential. 7mvservice manual download site
Due to the color grating slant green (1), at the end of the first test and green tube collector voltage, only a little more than 30 V, the base voltage 7.2 V (normal). 7mvservice manual download site
(2) remove the visual board M801, measured again edge look more at the end of the tube collector voltage 150 v, returned to normal. Tube green cathode and gate or the side of a filament, appear even much work five minutes for cathode and filament. 7mvservice manual download site
(2) side of the TV set on the table, even the very phenomenon disappeared. Inverted on the table to work again, also do not have even a phenomenon. To extend the life of the tube, the tube to rotate for 180 degrees after installation, troubleshooting. Didn't touch to omit adjustment, color pure, convergence and deflection coil, will only switch on both ends of the deflection coil. Color pure, gather all very good, just a center, the line center is changed again.7mvservice manual download site