Originally Posted by POfisher

I have a HD5 and this exact thing happened to me last night. I was sitting over a crappie condo for about 3 hours anchored and not moving. I saw several bait balls come and go. Then I noticed my depth went from 19 feet to 4 feet for no reason. Then it went back to 19. I white line came across my screen at 4 feet, like the sonar was seeing a new bottom. At first I thought it was a thermo reading of some sort, then noticed this happened on and off. I tried turning off the unit and even reset it back to factory specs. Once it came back on reading 4 feet and once it came back on reading 19 feet.
I thought "great" I've got me a piece of crap for a sonar. Then after stewing a few mins... I noticed the very large amount of shad around my lights. I fine tuned my settings (changed to 83 mhz) and saw the very large bait ball under my boat. When that bait ball was gone, I read the bottom.

Sometimes, you just gotta think about what's actually going on before condemning the unit. Mine actually did what would be expected. It was seeing a wall of bait fish and was reporting back to me exactly what I had asked it to do.

Best of luck with yours!