Troubleshooting The Echo Sounder - NorthStar Echo Sounder 491 Operation Manual

Troubleshooting the echo sounder

Contact Northstar Service to
upgrade to the latest version
of 961/962 software.
Configure NMEA Port 3 for
the 491. See Section 1 of
this manual for instructions.
1. Check fuses and circuit
breakers
2. Check power to 491 with
a voltmeter.
3. Verify that the data cable
between the 961/962 and
the 491 is properly wired
and connected.
The 491 and the 961/962
aren't communicating properly.
Check the wiring of the data
cable between the 961/962
and the 491.
Page 64
No echoes displayed when STAR key is pressed.
Is the
Advance
Speed set to
zero?
NO
Is the
961/962
NO
software
Version 3.0 or
greater?
YES
Has
NMEA Port 3
NO
been configured
for the 491?
YES
Check
OFF
the 491's STAT
indicator
FLASHING RED
GREEN
Figure 9: Troubleshooting the echo sounder (961/962)
Change the Advance Speed
YES
setting.
491 is communicating with
the navigator
1. Check transducer
STEADY
connector for the
GREEN
proper wiring.
2. If wiring is correct,check
transducer impedance
with an ohmmeter.
3. If the transducer is open
or shorted, replace it
There's a hardware problem
with the 491.
491 Echo Sounder Operations Manual