The Robertson J101A‑40 is an autopilot junction/control board used in marine navigation systems to interface the autopilot controller with rudder feedback and power supplies. Common failure points on this model include degraded solder joints or cracked traces around the power input, failure of the onboard microcontroller or its firmware, and loss of communication with the rudder encoder due to broken I/O pins. First‑check diagnostics: verify 24 V DC supply continuity and correct polarity; inspect the board for visible burn marks, cracked pads, or loose connectors; and use a multimeter or oscilloscope to confirm signal integrity on the rudder feedback lines before proceeding with firmware reflash or component replacement.[oss-gpt-20b]