6600 Lost RX/TX, & Pan/Waterfall Displays All bands & S-meter Frozen at 7

 -Radio and SSDR on but idle for 3 hours
-In the middle of a 30m cw QSO, while I was transmitting, the noise floor went from -120 to -80 but I could still hear the other station.  (not QSK)
-Pan/waterfall and S-meter display froze.  S-meter at 7. I could still TX and signed off with the other station
-I closed SSDR and powered down the 6600 and removed power for a minute. Also did a PC restart.
-Upon restart of 6600 and SSDR, the pan display/waterfall were blank and the S-meter still frozen at 7.  No receiver audio on any band.  Can not transmit on any HF band now.. CW sidetone works.
-I can select another slice and another pan display.  VFO changes all VFO displays when selected and reports freq changes to DXLabs commander.  S-meter frozen at 7 on all displays but no transmit even when selected
-6600 connected to the PC via direct ethernet connection.  No remote operations.
-Did not do a factory reset due to a warning to contact the help desk first.
-Followed Tim's instructions for taking the W10 1803 upgrade.  No problems noted.  I have made over 200 QSOs since I did that early last week.
-v 2.1.33.106 under W10 1803.
-power supply voltage is 13.76v at the radio
- Help Desk ticket submitted Sunday evening
-Radio was sent back after one month for a blown C65 on the power rail, no other damage then

Anyone heard of this? Advice?

Bill, N5IR