two new hummingbird unit issues

[bigwalleye99]

Bought a new 858c for the front and a 958 series DI and SI for the back. When using the terrova i begin to get lines in the screen, when i shut it off the graph works fine?? some how ther is interference, just clueless wher to look or if ther is a setting to play with. With the rear one, when i start the big motor and begin to power up is also begins to have lines showing up. Also after about 10mph is wont read depth. Running a 2025 prov and suggestions?? thanks

[Just One More Cast]

Try powering them with an isolated temporary battery, even if it's out of a lawnmower. That will isolate the issue if it works.

Get a filtered power cord from Humminbird. I had the same issue and this solved the problem.

[jeffbilodeau]

Same issue with my 998SI. When Terrova is running side imaging usually has faint horizontal lines very close together. Turn off the Terrova and clear as a bell....I just ordered the cable. I think the part number is PC11.