Question about JVC TM-2703SU 27" TV
My upstairs neighbour and I who do not share a connection for our TV's have developed the exact same issue on both our sets. At exactly the same time. My set is experiencing an issue with lines being displayed about 3 inches in width from the top of my screen. On most images the lines are hardly noticable, however when there is a long shot or a sceenary shot the lines are really noticeable. It appears that the lines are my TV's image flipped over on the same viewing surface. An example of what I mean is when the credits of a movie are scrolling they pan from bottom to top traditionally. When the credits get beyond my screens natual viewing range at the top they appear to flip upside down and continue scrolling top to bottom and stop where the lines are not present on my set. It's almost as if my TV has extended it's viewing range larger than my screen and to compensate it has flipped the extra part over on it's self. As well just below the flipped part which is about 3 inches in size there are static white lines where there is not image at all. However these static lines are pure white, with no variation. They are about 5 inches down from the top of my screen and are in this pattern. They almost apprear to be damaged pixle lines in the screen or in my display tube. They do not move, change color, or do anything but leave the image incomplete just where they are...I don't know if the image is not being place where the lines are or if the lines are covering them up but they are completly different from the lines mentioned in the above paragraph. This is the pattern of the static lines __ __ __ __ __ __ __ ______ __ __ __ __ __ __ __ __________ __________ The first set of lines appear to distort the image or extend the image so that it has to flip over on it's self. The second set of lines appear to be covering the image or preventing it from being displayed in the affected areas. Any info would be appreciated. Thanks X_Dusty_X
This symptom is what we called vertical fold-over. vertical fold-over is characterised by a white horizontal bar on the bottom or top of the raster due to the concentration or compression of the trace lines. it an image is present, the bottom or top portion is fold over. this is caused by a vertical deflection current with poor linearity, which compresses the trace lines at the bottom or top of the screen. this symptom is is caused by a defective sawtooth wave genetator circuit, or improper biasing or defective feedback circuit of the vertical drive or vertical output transistor/ic. the negative feedback circuit in vertical deflection circuit compensates for the linearity of the trace portion of the sawtooth wave. a decrease in the capacitance of the sawtooth generator capacitor is usually the trouble. but if you do not understand anything what i have written here, better bring it to a qualified tv technician for your own safety also. good luck!
Posted on Mar 02, 2007
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