Only have audio on left side.

[Demoninja]

Great that in terms of voltages everything checks out.

1. I turned the knob all the way up and measured the resistance and they both came up around 87K ohms.

2. By contacts do you mean the 3 metal parts that get pushed out when the headphone is plugged in? If so when you look at it from the under side, the "top" contact doesn't seem to move. By top I mean the one the white wire is soldered to from 10L.

[Paul Birkeland]

2. By contacts do you mean the 3 metal parts that get pushed out when the headphone is plugged in? If so when you look at it from the under side, the "top" contact doesn't seem to move. By top I mean the one the white wire is soldered to from 10L.

That connection feeds the left channel.  It might be worth double checking that your headphones do send the left channel to the left driver, and right channel to the right driver.

Beyond that, you will want to download a 60 Hz test tone and get the meter back out, then I can help you trace signal through the amp.

-PB