MFD will not recognize Radome – message “No Source Found”

[Helmling]

MFD will not recognize Radome – message “No Source Found”
SeaRay 340 Sundancer in covered slip with metal roof, winterized, 2 year old batteries on charger
Installed new transducer, I50 Depth, RMK-9, GA-150, and soon Ray70 VHF
Chart plotter, sonar, I50 Depth and RMK-9 work perfectly thru Backbone cables, 5 Way connector, and Raynet cables
Using a new “Test” battery (Group 24) Checked voltage - never lower than 12.6 DCV.
MFD and Radome are connected to battery terminals with in-line switches and fuses.
After many failures using the “Test” battery, connected to STBD battery bank (13.2 DCV) and same “No Source Found” message.
Checked Radome Raynet cable with multi-meter continuity pin recesses at each end and not all of them read continuous. Checked the Raynet cable supplied with the RMK and the MFD with more or less the same results. Did not write down the pin position numbers that did not read. Tried the other two cables to connect the Radome and MFD with same failures.
Verified 12.6 DCV at Radome end of power cable.
All cables are new, installed by me with utmost care.
Based on the SNs for the Radome and MFD, is software the cause of lack of communication, and if so, what downloads for the Radome and MFD do I need?
PN: T70243 Quantum Q24C Radome w/Wi-Fi and Ethernet 10M Power and 10 Meter Data Cable
SSID: 0360064 Passcode4922aXXX
PN: E70236-LNC a127 12" Multifunction Display with built-in sonar and Wi-Fi
SN: 095004