My Siny Trinitron G21M1 is producing horizontal lines across the screen

To clarify, are the 3 black lines horizontal (left to right across entire width of screen)? or are the 3 black lines vertical (top to bottom across entire height of screen)?

Horizontal lines are almost always the result of a failed panel, and no board replacement will fix the issue.

Vertical lines such as you have described (only 3) are probably also a bad panel. If the black lines were evenly spaced in a repeating pattern, it could be a mainboard or TCONN board.

Has this panel been cracked? or perhaps cleaned recently with too much water or cleaning solvent that has gotten the screen wet?

You may have to sell the TV for parts.

panel needs replacement, better go for a new tv

http://www.photofactondemand.com/set#4736

Hi There,
Sounds like your Horizontal Output Circuit is leaking current causing diagonal lines across the screen. I hope this will help and thank you for using FixYa!

Hi there!
Sounds like a power supply fault. You could try replacing all capacitors in the power supply and others areas around the line stage, with the same values. You may also want to check the tuner or "IF" circuit for dry joints. Hope this will help you. Kind Regards, JUS004

There is some electronic circuit problem with your TV. Best if you want to repair it you find a reputable TV repair shop. Sorry.

Picture is reduced to a straight horizontal line across the center of the screen.

What model camera do you have? A few years ago a large number of defective Sony CCD's were installed in many cameras from several vendors. The CCD's eventually deteriorate to produce the effects that you're seeing. If your camera is a Canon, there's a very good chance that Canon will fix this for you for free, including free shipping both ways. This is regardless of your camera's warranty status. Please check the following two links for more info:
http://camerarepair.blogspot.com/2007/11/canon-digital-cameras-showing-black.html

http://www.usa.canon.com/consumer/controller?act=PgComSmModDisplayAct&fcategoryid=225&modelid=13390&keycode=2112&id=29819

Applicable cameras include:
A40, A60, A70, A75, A80, A85, A95, A300, A310, S1 IS, S60, S200, S230, S330, S400, S410, S500, SD100, SD110, IXUS V2/300/400/430/500, IXY Digital 200a/300a/400/450/500

hi there, your set has a capacitor problem, most of it are on the horizontal section and video section., usually 100 microfarad electrolytic capacitor with a high voltage is damage. try to test some parts. ty

You need to call for service now that the unit still turns on,the problem will become expensive if you try to use it like this,right now the set might have loose conections in the power supply,horizontal driver transformer.ETC.Be safe and call a service tech.