Service Manual - Cenatel

The following schematic, illustrates the logic of control for the two SCART connectors.
The terms used in the schematic are described below ;
1. AUTO represents a situation where the television has self-selected its picture source. This could be when the
SCART SLOW SWITCHING pin has gone to a high state, and the AV 1 input is selected without the intervention
of the user.
2. FORCED represents the change of source which has been commanded by the user (using the EXTERNAL button).
The user always has priority, and can override the AUTO change of source by the television.
3. AV KEY represents the EXTERNAL button of the remote control, or on the television.
4. S/SW 1, or S/SW 2 represent the SLOW SWITCHING inputs of the first SCART (AV 1) or second SCART (AV
2), these each being pin number 8.
5. F/SW 1 represents the FAST SWITCHING input of the first SCART (AV 1), on pin number 16. The second
SCART, AV 2, input does not possess a FAST SWITCHING input.
The HIGH state of a slow switching input represents the request from the external source to be selected by the
television. Whether this is accepted or not depends on the position in the logic diagram. The general rule is that the user
always has priority, so the use of the AV KEY will always result in a defined logic path being followed.
Under certain circumstances, defined in the diagram, the change of state of a slow switching input will result in the
automatic change of source by the television. This change, such as the change from RF broadcast to the AV 1 input,
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