Diagonal lines on my screen(samsung 55" projection HDTV hcn553w)
Here's the link to the user manual;
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 :)
I ALSO HAVE RCA VCR VR556
AND WHEN I UDE THE HEAD CLEANER I BAOUGHT FROM RADIO SHACK IT STILL DOES THE SAME THING LIKE NO SOUNDS ALSO I CAN'T GET IT TO COME CLEAR LIKE IT SUPPOST TO.I WILL NOTE THIS IT IS SITTING ON TOP OF MY SATELITE DVR COULD THAT BE THE PROBLEM?