SERVICE SWTICH FOR VIDEO DISPLAY DEFLECTION APPARATUS

摘要

A sawtooth signal generator of a D.C. coupled vertical deflection circuit is responsive, during service mode of operation, to a first signal at a D.C. level that is indicative of vertical centering. During the service mode operation, the generation of the sawtooth signal is disabled and, instead, the generator generates a D.C. signal that is D.C. coupled via a vertical deflection amplifier to a vertical deflection winding in a manner to position an electron beam at the vertical center of a display screen.