NotTaR of Television Sets : Picture fine, no audio                  
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Audio Problems

Picture fine, no audio

First check that any muting control is not activated. This might be a button on the remote or set itself. If you have a headphone jack, it may have dirty contacts as plugging in a headphone usually mutes the speaker.

If the set is mono or only one channel of a stereo set is out, then check for bad connections to the loudspeaker. Test the loudspeaker by disconnecting one of the wires (with the power off!) and measuring its resistance with an ohmmeter (it should be less than 100 ohms - probably less than 8 ohms). Or momentarily touch a 1.5 volt battery to the speaker terminals - you should get a click or pop from the speaker.

Next, trace back from the speaker output terminals to the circuit board and look for bad solder connections or a loose or dirty connector.

If these tests do not reveal anything, you probably need a scope (or audio signal tracer) and schematic. Or at least the part number off of the chip. Is the final amp a chip also or just a transistor? Have you tested the transistor? If there is little or no buzz from the speaker, that would indicate a problem fairly near the output. If the tuner/if were bad, I would expect some noise/humm pickup from the low level audio stages. Get the part number off of the chip. If it is in a socket, check the contacts for corrosion or looseness.