Line down left side screen - Sony Bravia KDL-42V4100 42 in. LCD TV

your video card going or your moitor is

Check and replace all the electrolytic capacitors at its vertical output section circuit.

Most LCD and PLASMA sets use two boards (some combine them into one board) that drive the Display Panel (the entire front screen unit) so I would suspect one of yours is bad.

The other unpleasant possible cause is where the left board is connected to the Display Panel (entire front screen unit) you have a problem inside that Display Panel and that is fatal as there is no way to get INSIDE the panel---it can cause both lines and a dark picture on one side of the screen.

you likely have the "screen size" option set to allow the TV determine the best size (3:4 , 16:9, ...). Set it manually to 16:9 for HD channels or 3:4 for low-def channels.

The line should go away. This is a common problem on Samsung, Sony (Green line right side) and Phillips (yellow line left side).

most likely a misconnection between the main board and the dmd board. if not that, you'll have to replace the main board.

you need to look at your remote, you will see left arrow, right arrow, up and down, hit the arrow to the right, will see pickture moving over

This is a bad panel. The panel is very expensive to replace. It would be cheaper to buy a new tv. Sorry about the bad news.

My Hitachi TV Flat screen 42 EDT 4 1A has a one inch black line from the top to the bottom of the
screen on the left side. What or how do I fix it. I did blow it out with a air compressor as suggested by a local repairman.

i'm no expert by any means; but I wonder if it could be as simple as the reflective screening on the inside comming loose. I have a 65" and I took it apart to clean it. The reflective screening looked to me like it could be a weak point. Just a thought.

This can't be repaired, the LCD panel is a sealed unit. if you can't live with it then you need a new monitor