This Headphone jack assembly if working correctly is passive (some models have the DAC circuitry within the assembly). I would inspect the connector interface both sides for any damage. How about posting some nice tight focused pictures so we can see things too.
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[image|3606739]
If the connector interface is not damaged or corroded then the logic within the logic board has a problem which switches the signal electrically Vs mechanically.
This Headphone jack assembly if working correctly is passive (some models have the DAC circuitry within the assembly). I would inspect the connector interface both sides for any damage. How about posting some nice tight focused pictures so we can see things too.
If the connector interface is not damaged or corroded then the logic within the logic board has a problem which switches the signal electrically Vs mechanically.