I have a black line accross my LCD t.v. screen

bad lcd. replace the tv

that would be a failing tcon board on the back of the screen.you would need to replace this part but they are available on ebay the part number is on the tcon board. match the numbers a version number to get the matching board for the screen. tcon board is the board were the main wire cluster goes to the screen board this is the tcon board.

If you wish to get some details; visit the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
Line faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are similar, irrespective of its brand and screen size.

The blob is a phisically damaged part of the LCD screen. Unfixable, the screen must be replaced and it will be expensive.

Same thing happened to me but it was my cox hdtv/dvr box, I exchanged it and it resolved the problem.

You have a bad lcd panel.

If you wish to get some details; visit the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
Line faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are similar, irrespective of its brand and screen size.
Search the site by type in the "BRAND NAME" of your device; (Exclude the model number), in the "Search box at the top right of the display window of the Homepage" to get gathered related posts

I too had a black line horizontally across the screen (on a 52" d62). It was brand new and was as if the screen had been "pinched" at the end of the line and it radiated outward (in my case, the "pinch" was at the extreme left and line went out to the right, like a crack).

Mine was a factory defect (right out of the box) and was replaced (2 yr now and no issues). This line of yours may have been there from the start and maybe you just didn't notice it?? Not a slam, just an observation.

The model is a LN-S4041D. A 40 inch LCD. I can send you a photo but I can't get the file size small enough to post

http://home.earthlink.net/~oleg.filippov/ConvergenceFix.htm
http://cmpalmer.blogspot.com/2006/11/fixing-my-own-tv-part-ii.html