Tv has horizontal lines on top of screen.
You are seeing vertical retrace lines on the top of your TV screen.
There are mainly three causes for it. I don't know the age of your TV. The first cause is due to the supply voltage lack to the video output state. You can check it on the picture tube base card. You haven't mentioned about the diamension of your TV screen. So it can be say as a guess. If your TV is 27", the voltage mantioned above will come to about 245VDC. If there is a great voltage loss, check the smoothing capacitor to that supply, will normally come to the value of 10MFD 450V.
The second one is, capacitor related to the vertical output stage of your tv. It is in the circuit board. Normally these capacitors are situated in an area, which will get hot during working. As s result, there is a chance to the value change of their capacitance. It is best to replace all of them, as it may not cost too much. Before desoldering it out, mark the value of each capacitor is best. Normally replacing the filter capacitor 3300MFD or so,to the power supply to the vertical output Ic will solve this problem.
The third is related with the vertical output Ic itself. Just check all the soldering points in the vertical output section of your tv board. Anyway, resoder all suspected soderings by applying a little more solder, as bad solderings to the legs of the Ic or some other components also may the cause. OK.
Nov 10, 2010 |
Toshiba Standard (CRT) Televisions