No Sync Signal: Jrc Radar

Troubleshooting the "No Sync Signal" Error on JRC Marine Radar: A Comprehensive Guide

Introduction

• Flat line: Open circuit or dead driver.
• Noisy, chaotic signal: Corrosion or bad grounding.
• Missing every 3rd or 4th pulse: Intermittent magnetic pickup.

1. Inspect connector pins for corrosion or pushed-back pins.
2. Check for kinks or crushed sections of the cable.
3. Measure continuity of the trigger line (refer to your model’s pinout – typically pins 5–7 for trigger).
4. Replace cable if damaged.

• AZI Pulse Counter: Should increment smoothly as antenna rotates. If stuck at 0 → no sync.
• Sync Voltage: Should read between 2.5V–5V DC when rotating. If 0V or 12V constant → sensor or cable fault.

• With power on, measure for the presence of a sync pulse at the display end using an oscilloscope or logic probe (expect a TTL or shaped pulse on specified pin). If no pulse, test at the antenna end to isolate cable vs antenna.
• Check supply voltages to the antenna head (per manual) to ensure PSU delivering required voltages.

Verify Antenna Rotation: Ensure the radar pedestal is receiving the correct voltage. If the motor isn't spinning, the system cannot generate azimuth or heading pulses. no sync signal jrc radar