Upgrades to Existing Raymarine System on B35.5

[Tnauck]

I installed the converter kit as shown in my diagram and everything worked fined for about 5 minutes. Latitude, longitude and time were shown on the DSC VHF, but then the signal was apparently lost. The converter LED started flashing Not Connected/ fault sequence. It was also not listed on the device list under Maintenance/Diagnostics. I connected the MFD directly to the converter block in position 2 and the position and time information were again displayed on the DSC VHF, but now the MFD doesn't recognize the Autopilot. Could the new backbone cable be defective and still transmit power, but not data to the converter? I have updated the software for all instruments, p70 autopilot, SPX5 course computer and MFD to the most current versions. All suggestions would be appreciated. Thanks for your help.