If the screen is dark black with a bright horizontal line across the center then you have lost vertical deflection. You say "the screen goes black" so I guess that means the set comes on OK and then you lose vertical. That means the fault is intermittent (most intermittents caused by heat) as the set warms up the bad component or connection goes bad and stops the circuit it's in from working. To fix this you most often need a service manual lots of test equipment and know-how. Or the very good luck of having it be just a bad solder joint that is easy to find and fix. Not the kind of thing for a non tech to try. You will find danger inside your TV. If you go looking for that bad solder joint that might not even be there use great care. Unplug the set first and let it set for a while. When you get inside stay away from the high voltage wire they had 30 thousand volts or more on them and some of it may still be there. Take some digital pictures of the inside if you can so you can put the plugs you knock loose back in the right place and have a helper so he or she can give you CPR to bring you back to life if you make a big mistake. Also the CRT (picture tube) is glass and is thinest at the neck so USE CARE. To find a bad solder joint use a bright light and close-up (reading) glasses with a strong magnification. PS: I am not kidding about having someone with you. Good luck.
dcrandall222@netzero.net, October 2005
