Lafayette Telsat 140 no SSB XMIT

Hi Gang,
Interesting issue here. I have a Telsat 140 that will not transmit on side band. It does transmit with modulation on AM. It has receive audio and when you are transmitting in side band it does light the on air light. The driver and final have 13 volts on the collector in side band transmit. For some reason it is not passing audio from the mic jack.

Any thoughts?

Thanks as always!!!