Last week I had the same/similar issues you guys all mentioned. (Couldn’t pick up jig in 20ft, even with gain turned all the way up). I changed transducer frequency, reset defaults, made sure correct transducer was selected, switched to ice fishing mode. Nothing worked. So I switched to my backup depthfinder for the night and went home scratching my head. I suspected that maybe my transducer went bad.
Once at home I noticed a firmware update available, so I reset the unit to factory defaults and performed the update. After that I swapped batteries and made sure they were fully charged. Next time out on the ice I had the same issues, UNTIL I changed to ice fishing mode and reset to factory defaults again. That fixed it. Now it works perfectly again.
So my experience pretty much matches everyone else. (something with the four items below fixed my issues)
1. Make sure you have a good battery
2. Make sure you have latest firmware installed
3. Make sure you’re set in ice fishing mode
4. Reset to defaults.
If you’ve completed those items above and the unit still doesn’t act right, I would suspect a bad transducer and would find someone’s to borrow or get a new one, to eliminate that possibility.
All in all, that’s the first issue that I’ve had with my Helix over the two years using it now, and using a 788ci HD for 5 years prior to obtaining the Helix.