Products
Products
Company
Company
© 1998-2025 Fast Reports Inc.
Using a portable oscilloscope or high-frequency voltmeter, measure the signal. You should see a distinct, repeating square wave pulse.
The scanner uses an encoder to track azimuth (position) and sync time. If the encoder fails, the sync signal is lost.
Unplug and re-seat the connector, checking for bent pins.
Most radar signal failures stem from connectivity or mechanical wear rather than a total internal collapse. Worn Motor Brushes
If the motor does not rotate, you must determine if power is reaching the scanner.
This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later. JRC Radar problem-need help - Cruisers & Sailing Forums
Disconnect the SigCon cable at both ends. Using a known-good short coaxial jumper, connect the display’s sync output directly to its sync input (if the radar has a loopback mode). If the error disappears, the cable or slip ring is faulty.
The encoder, which measures the antenna's angle, is faulty or dirty.
Corrosion or loose connections in the antenna cable are the most frequent cause of "No Sync Signal" due to the harsh marine environment.
A "No Sync" signal on a JRC (Japan Radio Co.) radar typically indicates a communication failure between the scanner (antenna) and the processor unit . This error prevents the radar from properly synchronizing the received pulses with the display, resulting in no image or a distorted visualization.
If you have verified antenna rotation, checked cable continuity, and the diagnostic menu still shows zero sync pulses:
: This signal instructs the display unit's analog-to-digital (A/D) converter to begin sweeping from the center of the screen outward.
| JRC Series | Common Sync Issue | Likely Fix | |------------|------------------|-------------| | JMA-1000/2000 | Loose internal trigger connector | Reseat J301 on scanner PCB | | JMA-7100 | Corrosion on antenna rotary joint | Replace slip ring assembly | | JMA-5300/5400 | No heading pulse from encoder | Clean optical encoder disk | | JRC 1500/1800 series | Failed trigger transistor (Q12) on modulator board | Replace 2SC4706 transistor |
What is the of your JRC radar (e.g., JMA-1500, JMA-5200)?
Using a portable oscilloscope or high-frequency voltmeter, measure the signal. You should see a distinct, repeating square wave pulse.
The scanner uses an encoder to track azimuth (position) and sync time. If the encoder fails, the sync signal is lost.
Unplug and re-seat the connector, checking for bent pins.
Most radar signal failures stem from connectivity or mechanical wear rather than a total internal collapse. Worn Motor Brushes no sync signal jrc radar
If the motor does not rotate, you must determine if power is reaching the scanner.
This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later. JRC Radar problem-need help - Cruisers & Sailing Forums
Disconnect the SigCon cable at both ends. Using a known-good short coaxial jumper, connect the display’s sync output directly to its sync input (if the radar has a loopback mode). If the error disappears, the cable or slip ring is faulty. If the encoder fails, the sync signal is lost
The encoder, which measures the antenna's angle, is faulty or dirty.
Corrosion or loose connections in the antenna cable are the most frequent cause of "No Sync Signal" due to the harsh marine environment.
A "No Sync" signal on a JRC (Japan Radio Co.) radar typically indicates a communication failure between the scanner (antenna) and the processor unit . This error prevents the radar from properly synchronizing the received pulses with the display, resulting in no image or a distorted visualization. Worn Motor Brushes If the motor does not
If you have verified antenna rotation, checked cable continuity, and the diagnostic menu still shows zero sync pulses:
: This signal instructs the display unit's analog-to-digital (A/D) converter to begin sweeping from the center of the screen outward.
| JRC Series | Common Sync Issue | Likely Fix | |------------|------------------|-------------| | JMA-1000/2000 | Loose internal trigger connector | Reseat J301 on scanner PCB | | JMA-7100 | Corrosion on antenna rotary joint | Replace slip ring assembly | | JMA-5300/5400 | No heading pulse from encoder | Clean optical encoder disk | | JRC 1500/1800 series | Failed trigger transistor (Q12) on modulator board | Replace 2SC4706 transistor |
What is the of your JRC radar (e.g., JMA-1500, JMA-5200)?