What causes curved red lines on the display of Sony rear projection TV?

Question

We have a Sony rear projection HD TV. It has worked fine for 5 years. Recently, we noticed that there are curved horizontal red lines etched permanently across the display. Regardless of the input we are using (dvd player or cable box), these red lines are permanently displayed when the TV is turned on. Any ideas on what causes this and how to fix it? Is it something to do with cleaning some components?

Answer 1

if they are red and permanently etched as you say, then it sounds like you've burned a pattern into the blue and green crts. If you don't have an  extended warranty, then it will cost more than a new TV to repair it. If they are part of the display however, then they are most likely due to failed components in the convergence correction circuit.

Answer 2

Since they are curved, I suspect it is on the plastic front panel.  Can you detect them even when the TV is off?

Are they about the curve of the sweeping motiong you use when you dust off the screen?   If so you can try some careful cleaning

http://www.hdtvmagazine.com/articles/200...

Also, it could be gunk inbetween the layers.  There is an inner fresnel portion to the screen, with a protective outer layer.  On some TV's you can remove the front bezel to remove the outler layer and carefully clean between the screens.

If you think it is electronic, you can go to the SETTINGS menu of your TV, and turn the RED down as low as it goes.  If the red line looks a lot dimmer, then it is an electronic issue, and I don't know what you could do other than buy a new TV.

GoodLuck.

Answer 3

Since the set is 5 years old this will be a crt based rear projo.  Put the set on an unused video input.  Do the lines run side to side about 2-3 inches apart from top to bottom?  If yes then the this is one of sony's model with known bad picture tubes (all three).  Cost to repair out of warranty would be over $1000--not worth it.  

If the red lines are just in one area (with a picture back up)--say the top of the picture--then the problem is the convergence amp IC's.  Repair would be around $300 but if this is one of the models with the bad crt's--I talk the customers out of the convergence repair because they dont want to have to call me back in a short time just look at the lines in the pic (most likely like yours) and charge them to literally do nothing but look at it--never opening my tool box.

Model number something like  kp57ws500  kp51wt550

BTW--Don't ever try to clean between the screens unless you know exactly what you're doing----even the experts make it worse sometimes---and rookies ALLWAYS make it worse