If you are underway in zero visibility and the error appears, there is a dangerous but effective hack for older analog JRC radars:
The signal must pass from the rotating scanner to the stationary display via a rotary joint or slip ring. Over time, carbon dust or oxidized tracks cause intermittent sync loss. no sync signal jrc radar
If you have checked the junction box connections and verified the antenna is spinning, but the error persists, you likely have a hardware failure in the scanner unit. Opening the scanner pedestal involves handling high-voltage components that can hold a charge even when unplugged. At this stage, it is safest to contact a certified JRC service engineer. If you are underway in zero visibility and
A "No Sync Signal" error on a JRC (Japan Radio Co.) radar typically indicates a communication failure between the display unit and the antenna/transceiver. This often prevents the system from synchronizing the scanner's position with the display sweep. Common Causes & Solutions Marine RADAR Repair, Service, and Maintenance | SEANAV The signal must pass from the rotating scanner
Troubleshooting the "No Sync Signal" Error on JRC Radars The "No Sync Signal" error (often appearing as "TXRX(AZI) Error" on newer models) is a common hurdle for mariners using JRC Marine Radar systems. This error indicates that the display unit is not receiving critical timing or rotation data from the scanner, effectively "blinding" your navigation. Immediate Causes & Quick Fixes
When this signal is lost, your radar cannot determine where the bow is or how far the antenna has rotated. Use these steps to identify the culprit: JRC Radar TXRX(AZI) Troubleshooting Guide | PDF - Scribd