Trouble with Lowrance LCX-27C

I've been having trouble with my Lowrance LCX -27C the last few trips. It has been running fine but the last few trips, it is not showing the bottom or any structure or cover. It looks like it is getting interference from something but I've turned off my unit in the back and that hasn't helped.

My question is since I've tried both automatic and manual settings, what settings do most of you use to get your best readouts. I've used Lowrance for years but have never run into this before.

Every time I touch the trolling motor, it loses signal for a second. I can live with that but it's tearing me up when I'm trying to find my cover and can even be directly over a brushpile and can't get a read. I'm trying to tightline and can't see my brush until the unit in the back passes over it.

Taking a camera with me today so maybe I can get some pictures to post and be a little more clear of the problems I've been having. I hate to think I spent over $1,000 two years ago and it's going out on me.

Make sure you are running the latest software.
Make sure all connections are clean and tight.
Be sure you are powering it from the starting battery and not a trolling motor battery.

you say it goes off when you touch the trolling motor, Bill may have hit on part of the problem, loos wire, corroded wire, the depth finder may work better not hooked to the trolling motor battery.

With the first paragraph it sound like a bad ducer. I always use manual settings with fish ID off. But auto or manual wont make a difference with what you are describing. Also turn the unit on and place the transducer next to your ear and see if you can hear it ticking, if not its a ducer. Its usually not the ducer that goes bad, its the coax going to it. The wire will break internally