Mk164 & mk162

I have a MK164 and an MK162 that I finished assembling yesterday. I have power to both units and when I press the UP or DOWN button the LEDs in the MK164 respond (Left or right flashes on for a moment, indicating successful transmission I assume)… but I’m not getting any audio output.

The center LED flashes when I reset the MK164, but as soon as I press a button on the MK162 it stays on constantly and the left and right LED respond as indicated above.

Any ideas?

The MK164 microcontroller seems to function properly. Check audio section of the circuit. Make sure IC receives serial input from the PIC.