If you can tell me the of your JRC radar (e.g., JMA-5200 or JMA-9100 series), I can help you find a more specific troubleshooting guide or the correct part numbers. Facebook·FURUNO ECDIS specific
JRC service manuals outline a very specific troubleshooting procedure for rotation and reference signal failures ( TXRX(AZI) and TXRX(HL) errors). The process is:
An internal component failure on the modulator PCB inside the scanner, or the Signal Processing Unit (SPU) motherboard within the display console, can completely arrest signal processing. Step-by-Step Troubleshooting Protocol
Have you encountered this error on a specific JRC model like the
Open the scanner unit and display unit to check for loose terminals or water ingress. no sync signal jrc radar
Step-by-step diagnostic checklist (practical, prescriptive)
Incorrect configuration settings are a common and fixable cause.
If the issue is traced to the modulator board, inspect for visibly leaking or bulging electrolytic capacitors. Replacing these can often restore the trigger circuit without purchasing a whole new board.
If you can tell me the (e.g., JMA-5300, 1500) and if the antenna is actually spinning , I can provide more specific troubleshooting steps for your unit. Share public link If you can tell me the of your JRC radar (e
Imagine you are navigating a vessel through congested shipping lanes or poor visibility when suddenly, your JRC radar display stops showing a coherent picture—or refuses to transmit altogether. A message appears on your screen: “No sync signal” or similar indication of synchronization loss. The scanner may still be rotating, but the display shows nothing meaningful, making navigation a blind gamble.
While a failing magnetron usually causes "No Signal" or weak targets, a catastrophic short circuit inside the tube can trip the modulator board's safety logic, suppressing the sync line. 3. Step-by-Step Troubleshooting Guide
If the signals are present at the scanner but missing at the display, the interunit cable is faulty.
When the display stops receiving this signal, it triggers the "No Sync Signal" or "No AZI" (Azimuth) error, indicating that the scanner’s positional data is missing. Common Symptoms Radar display screen shows a "NO SYNC SIGNAL" message. The scanner unit is not rotating. The system powers on but displays no target data or echoes. 2. Troubleshooting "No Sync Signal" on JRC Radar Replacing these can often restore the trigger circuit
The “no sync signal” error presents itself differently depending on which specific radar model you operate. However, certain telltale signs are consistent across the JRC family. The scanner may rotate but no radar image appears on screen. A blank screen or static noise pattern is displayed, yet operational functions like range adjustment, gain control, and EBL/VRM markers still respond. The display may show the message “TXRX(HL)” or “No received Sync Source,” indicating the absence of the reference position signal. The radar picture may drift, appear warped, fail to update, or show no targets at all despite proper gain settings. In some cases, characters and text on the screen remain visible while the radar picture is completely missing—a strong clue that the sync signal for the radar video itself, rather than the entire display system, is compromised.
Troubleshooting "No Sync Signal" on JRC Radars: Causes and Solutions
The sync signal is often carried via a specific shielded wire or coaxial core within the main radar composite cable. Physical stress, sharp bends, or mast vibration can fracture this core.
Safety Warning: Radar scanner units contain lethal high voltages (up to 10,000V) inside the modulator circuit, even when turned off. Turn off the main breaker and wait at least 10 minutes for capacitors to discharge before opening the scanner.
(enter via password: often 1234 or consult manual):