I have a blue line problem with 50 inch sony wega.

sounds like it's toast http://community.sony.com/t5/Television-Picture-Sound/Vertical-Lines-of-death-KDL-52W4100/td-p/29582

your capacitors are are bad open it up check the capacitors with any bulges in them and then go to radioshack and buy the capacitor with the same rating to replace. It is actually very simple. If it is under warranty still take it back

If that blue hazy line is there in all inputs and no signal, you have a defective light engine. Contact Sony Customer Support because they extended the light engine warranty on some models.

turn down the picture level the blue line goes away

the vertical blue lines indicate some interference from other electronic gadgets near your tv. it started showing up on my sony grand wega when i installed my wireless modem. i almost ordered a new rear projection lamp costing over $100 but decided to experiment. i first moved my desk computer farther away from the tv then isolated the wireless modem router by placing it inside a small glass - the vertical blue lines became lighter in color so i dedided to find another small glass that fit inside the first glass container then put the router in the double glass - no more blue lines and my wireless modem router still works.
do some deductive thinking to figure out what's messing up your tv and isolate the interference.
good luck!

Replace the optical block assembly

Hello,

This problem is most likely related to the Optical BLock of the TV. There is a board, called the C board, that does all of the thinking for the optics of the television, and there are tests that can be run to confirm this.

Try pressing the MENU button (or WEGA GATE, HOME) on the remote control. If the menu that pops up has the same lines running through it, then it is definitely the Optical Block. If not, that doesn't rule it out completely. You can try Sony customer support, and they should be able to run you through some tests to confirm the exact cause of the problem.

Hope this helps you...

We had the free repair from SONY for the blue dots and splotches. It works great now but you need to hurry and contact them as the offer expires I believe in December.

blue spot is probably light engine. Bad news. Flashing depends on the amount of times your timer power light blinks

Yes...your light engine/optical block is shot... 1500 dollars.