: Secure all connectors in the pedestal and behind the display unit, specifically looking for corrosion or loose pins.
If it does not spin, check the motor fuses on the main power board.
The processor uses this signal to:
Check the multi-pin chassis plugs and sockets for green copper corrosion or loose pins.
Inspect the connector plug at the back of the radar display unit. Check for green or white corrosion. no sync signal jrc radar
One of the simplest yet most common causes is that the scanner motor is not running. The reference position signal is generated only when the antenna rotates. If the scanner is stationary, no sync pulses are produced. According to the JRC JMA-5212-4/6 Service Manual, a message indicating that a reference position signal is not output from the scanner triggers an automatic shutdown of transmission. If the motor is not running, the technician should investigate the motor itself, the relay circuit CSC-656, equipment cables connecting the scanner to the display unit, or the power terminal board circuit within the display system (CBD-1702A in many JRC models).
To resolve a "No Sync Signal" error in a JRC radar system, the following steps can be taken:
If the motor is not rotating, or if the internal electronics in the scanner are not working, the sync signal will be lost.
: If the antenna is not spinning or the rotation signal (Azimuth/AZI) is not reaching the display, the system cannot synchronize the image. Check if the motor is physically rotating. : Secure all connectors in the pedestal and
If you have verified antenna rotation, checked cable continuity, and the diagnostic menu still shows zero sync pulses:
Miller stripped the wire, re-clamped the terminal, and radioed down. "Try it now!" JRC Radar TXRX(AZI) Troubleshooting Guide | PDF - Scribd
Even when the motor runs smoothly, the sync pulse cannot be generated if the encoder assembly is defective. The encoder (also called the azimuth resolver or pulse generator) detects the angular position of the antenna and sends pulses to the display unit. A failure here means the processing circuit receives no position information. Service documentation lists the encoder as a suspect component when the motor is running but the reference position signal is absent.
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. Inspect the connector plug at the back of
A blown internal fuse, or a failed encoder optic on the transceiver board. Stops signal generation even if the antenna is spinning. 3. Step-by-Step Troubleshooting Protocol
Incorrect configuration settings are a common and fixable cause.
If the scanner spins but you still see "No Sync," the encoder is not sending the positional data.