JVC 33 inch tv- screen is black except a horizontal line=any help?

Answer 1

may be due to

vertical power supply failure

vertical output failure

vertical yoke coil open/short

vertical oscillator not working

wires leading to yoke may be disconnected

check ing all above may give solution.

Answer 2

A very common fault causing vertical collapse is dry joints on the vertical o/p chip which is usually a single in line device with a heat sink attached. This would be the cause maybe 90% of the time .