Quote:
Originally Posted by jr_tech
Since the sound IF signal is taken from the plate of the video output, and the sound is ok, wouldn’t that imply that the video chain up to that point (diode included) is functioning ok? 
jr |
The diode rectifies the AM carrier to make video and passes the FM carrier for sound....if the diode shorts it won't make video for the video amp but the sound will still flow down the chain normally....heck if the diode opens and passes just enough signal through capacitive coupling to the video amp you could still get sound.... video detector fails are fun.
If you.can inject and watch video on the vid amp side of the diode then you know the diode failed.