20 Most Recent Humminbird Fishing System, 787c2 Combo Without Gps 4066801 Plus - Page 2 Questions & Answers

First steps (you may have done done) check all wiring connections ,transducer, power,ext. at both ends. Attempt power up again. No change. Call 1-800-633-1468 with model & serial #'s. OR Disconnect all cable connections from unit and with a strip of aluminum foil short out all the connections on the 898c.(not the cable). Attempt power up again. If unit will let you go to 'System Status' screen & record. Hope your unit works.

Hi Ken A little wiring 101 is in order here I think. NMEA out (+ and -) from your GPS goes to NMEA in (+ and -) of your VHF. Hope this helps you out

Try a contact spray.

Normally a new clean faced 1 KW thru-hull transducer works to 3,000 feet ( 914 meters). Maybe the impedance of the transducer and electronics driving it do not match. Connecting cable too long? Poor connections. Look at plug pins to see if any are bent.

Be sure you have your unit set in "max mode" and run it on 200khz frequency see if this makes any difference. Also be sure your unit is wired directly to your battery not through a switch or fuse panel as this can rob your unit of voltage, impacting the strength of your sonar signal.

You need to set the transducer lower. When at speed, the hull of the ship raises up out of the water and hence your transducer is probably not deep enough at these times to give a proper reading.