i'm sure Hummingbird has a reset sequence like Lowrance. With my Lowrance unit on offshore boat anything works improperly I simply reset the unit ( had two differant models) and everything is fine. Maybe happened 2-3 times in 5 yrs. But on inshore boat I've replaced at least 2 units and third is not turning on now, less than a yr old. Sent 1st one back and Joby " repaired" it in 4 mins while I waited on phone. Called him next time and he said send it in for repairs for so ridiculus amount, soi returned it to West Marine on extended warranty. I did renew the warranty, thank god because i returned the 2nd one 1 1/2 yrs ago and now that one needs o be reset. I'll just return it but ould rather reset it myself.