No Sync Signal Jrc Radar May 2026

Troubleshooting the "No Sync Signal" Alarm on JRC Marine Radar

    • Encoder/pickup sensor (Hall effect or optical) that generates the once-per-revolution sync pulse has failed.
    • Scanner control PCB (e.g., JRC part: NJJ-1776 or similar) not processing trigger.

    Crucial distinction:

    This is not the same as "No Video Signal." You can have video (echoes) and no sync (so the image spins or is random), or no video at all. "No Sync" is an azimuth/timing problem.

    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.

    If the motor is not rotating, the scanner cannot generate the synchronization pulses. no sync signal jrc radar

    • Troubleshooting the "No Sync Signal" Alarm on JRC Marine Radar

  • Crucial distinction:

    This is not the same as "No Video Signal." You can have video (echoes) and no sync (so the image spins or is random), or no video at all. "No Sync" is an azimuth/timing problem.

    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.

    If the motor is not rotating, the scanner cannot generate the synchronization pulses.

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