Why is there no picture but sound on my tv?

The problem is vertical failure. Vertical output section to your TV ahs the fault. You ahve to check the vertcial output circuit for any component failure or loose solderings.

You have some bad capacitors. They are located very near and next to your vertical IC. I would guess you would have to replace maybe four of these! Thanks for asking!

Did you mean the picture is collapsed only in the middle horizontally(white line appears on the middle part of the screen)?
If that is the case, maybe vertical IC failed or loose connection.

Fault in HZ Deflection Stage check yoke also

Vertical hold circuit is failing.

Check capicitor in vertical hold circuit. You should have solid knowledge of electronics repair before attemping repair. TV's can emmit harmful radiation, and produce voltages up to or in excess of 30kV.

Hi I had the same problem. Broken white lines across the top of the screen. This is called overscan. You need to go into the Setup menu, other settings. 16:9 overscan needs to be on. Hope this helps.It solved our problem.

I wouldn't attempt as the capacitors on a tv store around 25000 volts this is more than enough to kill you and they keep there charge even when the tv is off. Either take it to a repair shop or put that money towards buying a new tv - Do not even attempt to open the tv. (It sounds like maybe a tube has gone or the electromagnet that makes the beam move vertically is gone.

You need to consider the following tips herein as follow:

1) Field collapse (horizontal white line on screen)
R710 dry joints. Same as C2146TN & C2546TN problem solved with thanks to Mike G & Barty. Power off/unplug. Get to circuit board underside with aerial socket up-R710 is near top and right of centre-cluster of 4 joints best resoldered
2) Picture is horizontally narrowed and deformed
Capacitor C2913 (390nF, 250V) on the deflector PCB had lost capacity

Please let me know any update

caution whenever you see horizontal line please reduce brightness of your tv for safety of crt. your problem in vertical section only mostly due to loose contact in connector,print or loose components.

Sound like you have to turn down the G2 (screen)controls. They are turned up too high.