Insufficient voltage can cause the scanner to fail during high-load transmission, leading to a loss of sync.
: Even if the motor rotates, a faulty encoder may fail to output the actual rotation (AZI) signal to the display. Wiring and Connectivity : no sync signal jrc radar
The "No Sync Signal" alarm on a JRC radar is a critical fault that stops all target detection. Most cases originate in the scanner’s azimuth encoder or the signal cable. Systematic testing – from antenna rotation to diagnostic monitor – will isolate the problem. While simple connector cleaning or resetting may restore operation, encoder or display board failure is common on older units. For reliable navigation, treat this alarm as urgent and do not sail without a functioning radar or an approved backup. Insufficient voltage can cause the scanner to fail
In CRT-based JRC radar models—which, although aging, remain in widespread service—the display itself requires horizontal and vertical sync signals to paint the radar image. If either of these is interrupted, the result is a blank screen or a warped, drifting image. The JRC JMA-2343 Instruction Manual explicitly identifies “interruption in the synchronizing signal for horizontal signal (HS) and vertical signal (VS)” as a cause of screen anomalies where characters and markers appear but no radar video is shown. Most cases originate in the scanner’s azimuth encoder