Abstract: A method and apparatus for testing the horizontal drive stage of a cathode ray tube display where the horizontal drive stage has a drive output which is directed to the base of a horizontal output transistor. In the method and apparatus, the output from the horizontal drive circuit is disconnected from the base of the horizontal output transistor and is connected to the apparatus of the present invention. The apparatus includes a load which simulates the load normally provided by the base of the horizontal output transistor. A meter differential amplifier is connected across the load and readings therefrom are projected on a display. The horizontal drive stage is then energized and readings from the display are compared to known operating requirements of the base of the horizontal output transistor.

Abstract: The horizontal output stage of a television receiver is tested by denergizing the receiver so as to remove B+ voltage from the horizontal output stage, and then powering the horizontal output stage from an independent low voltage DC power supply through a switch which is turned on and off at the horizontal sweep frequency to permit making measurements of operating parameters of said horizontal output stage.

Abstract: A composite test signal which consists of the combination of four audio modulated carriers is developed and injected into the stereo audio circuits of a Beta type VCR. The audio output of the VCR is observed or listened to in order to determine if the circuits downstream of the point of injection of the test signal are operating correctly.

Abstract: The chroma circuits of a VCR are tested by replacing the video signal from the video heads of the VCR with a composite signal from a test pattern signal developed by a test instrument, which composite signal includes a chroma signal which is phase rotated in response to a chroma reference signal from the VCR. The chroma reference signal from the VCR is used to control the chroma signal in the composite test pattern signal.