My CRT TV displays a single horizontal white line across the screen. It will flicker and try to display the picture. If you smack it you'll get a quick picture then back to a line. After about 10-15 minutes of warming up, the full picture will display and stay on (no more line)

try changing picture size

If your LCD TV or monitor has stopped working, or is displaying one of the following
symptoms, then it's a candidate for some new capacitors
- Flickering screen
- Screen image disappears after several seconds
- Dim screen
- Slow start
- Power LED on, but no picture
- Unusual colors and/or lines
The primary cause of LCD TV and monitor failure is caused by faulty capacitors. You can
examine the capacitors in your LCD TV or monitor and actually see if they are bad.
If they appear bulged on top, then they need to be replaced.
New capacitors will solve a host of problems in LCD monitors and TV's and will extend the life
of your monitor or TV by several years.

Take it to a repair shop.

Vertical retrace lines is the problem. Thin white lines runs across the entire screen, at about an inch apart to each other. Check its video output supply voltage. Reduce the screen voltage to a little bit down and check. If you still wish to know more about this fault, check this site. Pull up older posts there.

If it is just a collapsed picture and view as a white horizontal line across your screen. Loose vertical IC connection or is start ailing. Best is to reflux its pin with a new lead or resolder it.

But I don't recommend you do it yourself if you don't have experience doing it.

Nasty voltages may caught you.

Your vertical deflection IC is bad.

Hi,
I hope your TV model is Sony KV-G21M1 and you see color bars as horizontal lines across the screen.
Let me now are you tech guy or know how to repair TV to guide you further.

bad vertical chip ic

Middle going across the screen from left to right??
This unit is plagued with bad solder connections in the comb filter board and flatpack underneath the comb filter board. These connections can cause any odd number of problems in video display. If it is that it's not expensive - virtually no parts. If it's a single line across the screen could also be the vertical circuit involved.
My suggestion is to have it estimated at a reputable shop and take it to them rather than the more expensive pu/del charges.
If you would like go to http://www.nesda.com/locator/state_search.php and locate a servicer from there. Kinda like going to the AMA to find a doctor...
Hope this helps!
Bill

I have a similar problem on my CRT computer monitor (AcerView 76c). It is an old screen and I think it is just at the end of its life, much like your TV. Having some background in physics, I would be pretty sure that the problem is with the cathode ray tube's vertical deflection system. The horizontal deflection electrodes are working while the vertical one is not. This results in a display of a single horizontal line (or in my case, a few superimposed) in the centre of the screen. Where both X and Y (horizontal and vertical) deflectors fail then the electron gun firing would result in a single bright spot in the dead-centre of the screen.

So really, we have no choice but to move on and buy a new set as repair is probably just as, if not more, expensive than replacement with a new device. Seeing as your post was in 2007, I hope you managed to solve the problem.

Best wishes,
SZ (Sydney, AUS)

try adjusting the screen control down..if this has no control unit may have a bad video drive circuit or possible bad crt or fly back transformer ...just a wag