The picture seems to be sliding down the screen of my Samsung HCN553W, I can still watch it except for the top 4-5 inches in the top left corner, it's black. Does anybody have any idea what it could be?

You now have a 55" parts unit !!! A replacement 55" panel will most llikely cost as much as a new set !

I have got Samsung Plano 29 inch tv. I see redgreen and white color lines at the top of the screen.this slides down till the middle of the screen. Please suggest

If you are seeing light then the back light is working. Can you get a menu?Do any of the other video inputs work? If no video but has backlight and no men or any on screen display replace main board.

This is a common problem. Your convergence has gone out.

Common symptoms are...

1) 3D Video
2) Warped Video
3) Convergence menu does not adjust the red or blue correctly.

Go here for a solution...

http://www.fixya.com/support/r2861627-updated_convergence_problems_amp

Faulty light engine assembly
http://guides.fixyourdlp.com/samsung/bp96-01579a.php

The convergence output IC's need to be changed. A very common problem with all projection tvs.

tv has double image color red and a curl line on left upper corner also sometime in middle of tv it has line

You have a burn in problem from watching widescreen movies.If you have access to a signal generator or tv setup disc run a perfectly white screen on the plasma for about 30 min.This should help even out the pixels on the display.

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.

Here's the link to the user manual; http://org.downloadcenter.samsung.com/downloadfile/ContentsFile.aspx?CDSite=us&CttFileID=32370&CDCttType=UM&ModelType=C&ModelName=HCN553W&VPath=UM/200310/20031002105141187_P55A_00054A_0410.pdf Check page 28 and 29 for convergence instructions. Give it a try to see if it makes any difference. Check page 27 for the "perfect focus" feature and see if that helps. Could you take a photo of the "diagonal lines" on the set and post it - might help? If you open a menu on the screen, does it also have the lines across, or is it clear as normal. Check page 64 for how to run the demo, and try that. Have you recently unplugged the set from the mains power supply, left it for at least 15 minutes (preferably two hours) then turned it back on? if not, try it and see if you get any change. Check page 38 for the usual video settings - play around with them and see if any significant change? Check page 39 and set the "automatic picture setting" to standard, if it isn't already, and something else if it is - see if you get a change. Check page 40 for the colour tone adjustment - probably won't change anything, but worth a play in case. Check the bottom of page 46 about channel fine tuning - reset at least a couple of channels to 00, see if that makes a difference (long shot). Does the screen itself need cleaning? recommended is just a clean dry cloth - basically have a good close look at the screen when it is both on and off, to see if there are any marks that might be causing the problem - in particular has it possibly been cleaned with a solvent or too aggressively cleaned in a diagonal direction? shine a light on it at a few angles to check, and look from a few different angles too. Check by moving or turning them on and off if any other electric or electronic items near your tv may be causing the effect - speakers perhaps. Move speakers to check. A way to check other items is to totally cut off the electric supply to the whole house for a couple of minutes, except one circuit into which you can plug the TV and a picture source. See if you get a perfect picture - if so, start switching circuits back on 1 by one until it changes. Hope this helps - I think a photo would help a lot :)