Troubleshooting - Furuno CH-250 Operator's Manual

6.6

Troubleshooting

The table below provides common symptoms of equipment troubles and the means to rectify
them.
Symptom
Cannot turn on the
power.
Bottom echo becomes
irregular.
Weak echo
Somewhat strange
color
Picture contains noise.
Picture does not
change when tilt angle
is changed. (Bottom is
not displayed in vertical
fan picture when
bottom is flat.)
6-4
Check cable between transceiver unit and display unit.
Check ship's mains.
Have a suitably qualified technician check the fuse in the transceiver unit.
Rough seas. Distance to the bottom changes due to rolling and pitching.
Long range selected. Transmission period is longer so ship's pitching and
rolling are apt to affect detection of echo.
Output power set to minimum. Set to maximum, on the COM1 menu.
Excessive TVG. Readjust TVG on the appropriate menu (HORZ, VERT,
ES). Note that readjustment of TVG is necessary when gain is adjusted.
[BRILL] key setting too low. Increase brightness with [BRILL] key.
Equipment not grounded properly. Check equipment ground.
Power cable is too close to the signal cable. Relocate power cable or
signal cable.
Debris may be on sea surface. Reject unwanted noise with the
interference rejector on the COM1 menu.
Problem in tilt mechanism or control line. Contact a FURUNO agent or
dealer for advice.
Check, Remedy