[TenTec] Omni C - No TX

[Jeff Stewart]

    While adjusting my MFJ antenna tuner, my Omni C kicked out of transmit (too high an SWR I assume).  In the past, just shutting the rig down then powering up would reset it.  Now every time I key the mic or use the lock position, it shuts down but will return to receive when unkeyed.  The Omni and the 280 power supply both turn off on transmit but works fine in receive.  Both the fuse on the power supply and the radio check fine with an ohm meter.  What have I blown? ( I do have the owner's manual but I there's no troubleshooting section.

Thanks,
Jeff
http://www.qsl.net/ka9dad/