Explain the possible causes of the following faults in a TV receiver – NABTEB QUESTION

1. Picture rolling up or down the screen
Faulty vertical and horizontal oscillator

2. Pictures divided into segment with diagonal bars
Faulty horizontal oscillator and AFC

3. Picture drifting to the right or left
Faulty sync separator, video stage and Automatic Gain Control Stage.

4. No sound but clear picture
Faulty sound section, e.g. in sound IF, amplifier and loudspeaker.