Onwa KF-667 - Manual (Page 30)

4.2 Basic Troubleshooting
The troubleshooting table below presents common problems and the means to restore normal
operation. If normal operation cannot be restored do not attempt to check inside the equipment.
Basic troubleshooting
If Then
Neither echo nor fixed range scale appears
check battery voltage.
check fuse.
check battery terminal for corrosion.
check that power cable is securely
plugged.
No echo but range scale shows
check if transducer plug is firmly
connected.
Echo appears but no zero line check if range shifting is set to “0".
The equipment shows signs of low sensitivity
check if gain setting is suitable.
check for air bubbles or marine life
attached to transducer.
check if water is dirty.
bottom may be too soft to return proper
echo.
No water depth readout is shown check if bottom echo is painted red or
reddish-brown.
check if bottom is displayed.
check if transducer/transducer cable is too
close to engine
check unit ground.
check if there are other echo sounders of
the same frequency nearby.
Water temperature indication*is
absent or unrealistic
check that equipment plug is securely
fastened.
check position-fixing equipment.
4-3
*Requires external equipment
check that sensor plug is securely
fastened.
Position indication*is absent or unrealistic
Much noise or interference is present
check if display speed is set to"0".