No Sync Signal | Jrc Radar !!top!!

When you see that dreaded text on the JRC display, remember: The radar wants to work. It is simply asking for the starting gun. Find the sync, and you find your way home. Disclaimer: This article is for informational purposes by qualified marine electronics technicians. Always refer to the official JRC service manual for your specific model (JMA, NCR, or JMR series) before performing electrical work. High voltage exists in radar scanners even when powered off.

For technicians: Never trust a multimeter for this diagnosis. You need an oscilloscope to see the pulse. For vessel owners: Budget for a spare SigCon cable and encoder brush kit. For crew: Learn the audible rhythm of your scanner—a change in that rhythm is your early warning before the "No Sync" alarm appears. no sync signal jrc radar

Technician used a USB oscilloscope to log the sync line for 1 hour. The log revealed a 200ms dropout every 697 seconds (coinciding with the air conditioning compressor cycling on the bridge). When you see that dreaded text on the

Introduction

For any vessel operator, from coastal freighters to ocean-going tankers, the radar is the primary source of collision avoidance and navigation safety. JRC (Japan Radio Co.) radars, known for their ruggedness and reliability, are a staple in the wheelhouse. However, even the most robust systems encounter faults. One of the most cryptic and frustrating alerts a technician faces is the error on a JRC Radar display. Disclaimer: This article is for informational purposes by

The display processor’s power supply had a faulty filter capacitor. When the AC compressor kicked in, mains voltage dipped 5%, causing the sync detection circuit (which used a 5V linear regulator) to brown out.

Replaced four 2200µF capacitors on the display PSU board. Total cost: $12. Total downtime: 4 hours.