Tv on appears black screen with a bright horizonal line in the middle sometimes with voice

You will have to resolder the vertical IC and in most cases replace any capacitor that is near and next to the vertical IC. There may be three capacitors that will be replaced, And while you are in the process of reworking the board inspect for any and all grounds that may need resoldered. You will have to look very close to find these. And you should search the deflection side of the board for two capacitors that have a 160 volt to 250 volts at 1MF, or 2.2 mf or 4.7Mf. By now these little guys are weak and need replaced. Thanks for asking and show a few hands of support!

Hi. The condition you have described is field collapse, sometimes referred to as frame collapse. Common causes are dry solder joints on and around the area of the IC (Integrated Circuit), which controls horizontal size, failure of the power rail supplying voltage to the IC, usually an blown or out of value electrolytic capacitor, an open circuit resistor, or the IC itself, Component number LA3830. Hope this information is of some use to you. Good luck.