JVC A56P575

Hi
Check its back-light CCFL lamps. Gopakumar Gopalan Google

It is a calibration problem, let me see if I can find some schematics for your tv.

The screen voltage to the picture tube is more than normal. Adjust it by the help of screen pot-meter integrated with Line Output Transformer. Visit the site named 'Electro-help' for more details. Check this link and select the site named above. View it in 'Flip card' option, which can be selected from the drop down box menu at the left top corner or the display window. It will make search easy.

It sounds that the main power supply section to your TV has the fault. The horizontal thik lines that appears crawling down across the screen should be of video 'HUM'. Have you replaced the main filter capacitor at the power supply section? If not, replace it along with the main rectifier. The AC power is rectifed by a bridge and applied ot this main filter capcitor. It will have a capacitance value between 120 to 350MFD 450VDC. Check this section. Measure the rectifed DC voltage acorss this main filter capacitor. It should be around 350VDC, if your home power supply line is 220VAC. If it is 110AC, this DC voltage will be around 165VDC; and it should be. If rectified DC voltage found lower than the input AC voltage, replace the rectifier bridge. In some sets, this bridge section have four diodes. Some other circuits, a bridge rectifier stalk may be used.

vertical output ic needs to be resoldered. careful leaving that bright line displayed on the screen as this will cause a permanent phosphor burn into the tube. this can not be corrected once burned unless you replace the tube. mch

Convergence problem.

This is for the original problem.. Not the second post.

It's a problem in the horizontal deflection circuit. The parts will be available, but you will be in for some daignostic repairs also to find out why it failing or if it has failed on it's own.
There should be a few caps near the IC (an LA7840) that could also be causing the problem. Click the link, it will make it easier to locate the part inside.

This is the kind of repair best left to a TV tech, but get it done now and it won't cost anywhere near as much as it will later.

I believe i have the same problem myself. When my TV is on any of the Component Inputs without my DVD player turned on i usually get the normal green screen. But now that is a dip in the green at the top of the screen from the top left to almost the top right and black pushing down on the dip. Almost like a green curtain was sagging at the top and you can see the black behind it. It does this on every input and distorts every picture you see. The distorted picture has all the green slightly off from where the rest of the picture is and where the dip at the top of the screen is there is somtimes purple instead of black.

I know the basics of how the picture gets onto the screen and its my guess that the Green "gun" for lack of a better term and somhow come loose, or been missaligned to a great extent. I would love to find an answer to this problem, and anyones best guess as to how much a repair man will charge, just so i know the ballpark.

your main filter capacitor in power supply has gone defective.

just replace it .

every thing will be normal.

good luck.

 

you know its in vertical section, try to look for a capacitor and changed it, this is more of a capacitor problem.