E120/SeaRay Navigator Upgrade ?

[rvaupel23]

Everything except the new radar is now connected and everything is working except for one (new) issue:

What's working: CAM220 is flawless, legacy S2G AP is integrated via ST converter and I can control it from the new MFD's, the GA150 is providing a position fix (even through the building's roof that my boat is currently stored in), and the legacy Ray240 is picking up the GPS fix through the NMEA 0183 leads/connections.

What's not working: Using the E66066 adapter for the legacy DSM300's transducer (the DSM300 having been removed) I'm no longer able to obtain depth/sonar imaging and the water temp displays a readout for a few seconds then goes blank for a few seconds, back and forth.

What's most odd is that until today the fish finder functionality was working just fine, albeit the boat is out of the water. I was getting a steady blue sonar stream, constant depth readout, and a constant water temp readout. The only setup change made today was the integration into the STng backbone of a SmartCraft NMEA 2000 Gateway. (Which appears to be working despite not being able to fully test, again, as the boat is out of the water in storage.)

That said, in an effort to troubleshoot I unplugged the gateway from the SmartCraft backbone and the problem still exists. I also disconnected the VesselView's NMEA 0183 leads that were previously capturing a depth readout from the MFD in an effort to isolate the issue. Didn't work.

The MFD bounces between a solid blue screen (no streaming) that gives no depth reading and says "internal sounder" in the top left corner, to a white pop-up that says "Selected sounder unavailable". And repeats the cycle every few seconds.

Any ideas what could have caused and/or be the issue?