150m Ro-Ro cargo. Radar: JRC JMA-7322-6. Symptom: Intermittent "No Sync Signal" every 15 minutes, lasting 2 seconds—just enough to lose target tracking.
Insufficient voltage can cause the scanner to fail during high-load transmission, leading to a loss of sync. no sync signal jrc radar
To fix the problem, you must first understand the signal chain. In any analog or hybrid radar system, the scanner (antenna unit) and the display processor must remain in perfect synchronization. 150m Ro-Ro cargo
| Step | Action | Expected Result | |------|--------|------------------| | 1 | – Is the antenna rotating? Listen for motor hum. | If not rotating, check motor, belt, and power supply to scanner. | | 2 | Check scanner cable connections at both ends. Look for bent pins, corrosion, or water ingress. | Clean with contact cleaner. Check continuity of sync pair (consult your JRC manual for pin numbers). | | 3 | Perform a "Heads-Up" bearing test – Manually rotate the antenna slowly while watching the display’s bearing readout (if any). | If bearing changes erratically or not at all, azimuth encoder is failing. | | 4 | Access the diagnostic menu (JRC: usually hold Menu + Enter at power-up). Navigate to "Scanner Monitor" or "Pulse Detect." | View live sync count. If zero, signal is not reaching the processor. | | 5 | Substitute test – If you have access to a known-working scanner of the same model, connect it directly via a short cable. | If sync returns, the fault is in your scanner or ship’s cable. If not, the display processor is faulty. | Insufficient voltage can cause the scanner to fail