Cable wiring diagram

[Best Mate]

I have purchased a 2004 trawler and have Furuno Radar that will only pick up clutter, no targets. Occasionally, it will work on low ranges but very seldom. I have checked all of the connections and grounds, removed and cleaned all of the connections in the radar antenna unit and performed a factory reset on the multifunction display. I have run a diagnostics test on the MFD also with no issues, but still have the same problem.
I believe there is only one continuous cable running from the lower station (master) to the radar antenna unit (approximately 30 ft). I would like to ring out each pin from the MFD cable connector to each plug in the antenna assembly to eliminate a cable issue but am having difficulty locating a wiring diagram of the cable.
I believe I can purchase a used replacement antenna unit but would like to determine where my problem is before spending several thousand dollars on an older system. If the cable checks good, is there a service center that can troubleshoot and repair this unit? I am currently traveling by boat in the panhandle of Florida, heading north to Kentucky.

2004 Furuno 1933C Model RDP 139 Navnet Radar/Chartplotter C-MapNT
Radar antenna unit Type RSB-0070, SN R122-6250, FCC ID ADB9ZQERE064
Furuno Cable 6537-0 (printed on cable jacket)

 

[Deep Blue]

Best Mate,

I have attached a copy of wiring diagram between a NAVNET VX1 Processor and RSB0070 Gearbox. This should help you when checking continuity of your Radar Cable/Assy

-Deep Blue

 

[Best Mate]

Thank you! Do you know if circuit boards are still available for these units and if there are any service centers that can bench test and replace a failed board?

 

[Deep Blue]

Best Mate,

You can send in any PCBs for testing to our Service Center located in Camas, WA.

-Deep Blue

 

[Best Mate]

Great! Thank you!