3.5mm Jack Left Channel Not Working

Hello!

Many thanks for your fantastic guide on the Samsung GNex teardown; it has allowed me to replace the speaker module. However, this has not cured the missing left channel on the heasphones!

Is there another component that could cause this failure, that I could potentially purchase and replace?

I believe this is not a software problem, as the problem is consistant across several Android ROMs, which leads me to suspect a hardware problem.

Hope you can help, and thanks in advance!