This error typically appears on JRC’s JMA-5000, JMA-7000, JMA-8000, and similar series. It indicates the processor unit (scanner controller) is not receiving or cannot lock onto the synchronization pulse from the rotating antenna scanner.
Inter-cabinet cables—especially the main scanner cable that carries power, sync signals, and video—can develop internal breaks, shorts, or corrosion over time. Signs of water ingress inside connectors or cable outer sheaths demand immediate inspection. Damaged cables should be replaced with factory-specified equivalents from JRC.
Interference & grounding
In conclusion, a "No Sync Signal" error in a JRC radar system can have significant consequences on radar operation, leading to inaccurate measurements, loss of target tracking, and system instability. Understanding the causes and effects of this error is essential for effective troubleshooting and maintenance. By identifying and addressing the root cause of the error, radar operators can ensure reliable and accurate operation of their JRC radar systems. no sync signal jrc radar
Inside the scanner pedestal, JRC uses either:
Modern JRC radars allow you to set rotation speed (24, 36, 48 RPM) via software. If the scanner is physically rotating at 24 RPM but the display is set to SCAN SPEED: 48 RPM , the sync timing will be rejected as invalid, triggering the alarm.
For users with advanced electronic skills, component-level diagnosis is possible: This error typically appears on JRC’s JMA-5000, JMA-7000,
Use corrosion-inhibiting grease on connectors and ensure the radar head is properly sealed.
: This signal instructs the display unit's analog-to-digital (A/D) converter to begin sweeping from the center of the screen outward.
No power reaching the motor/transmitter, preventing operation. Signs of water ingress inside connectors or cable
: Ensure the vessel's batteries are fully charged or test while connected to shore power. Common JRC Signal Path Signal Type Description Symptoms if Missing Trigger (Sync) Timing pulse for pulse transmission No echoes on screen; range rings missing AZI (Azimuth) Indicates antenna rotation speed "AZI Error"; image does not update or is smeared HL (Heading Line) Marks the "North/Bow" position Image is inverted or 180° off Important Safety Warning
Display unit checks
Corrosion or loose connections in the antenna cable are the most frequent cause of "No Sync Signal" due to the harsh marine environment.
If the scanner is spinning but the error persists, the issue might be with the azimuth encoder , which generates the sync signals. Phase 3: Cable and Internal Components
The processor uses this signal to: