today turned on the fish finder tracker wide eye first it would not power up . my buddy says hold the power button down for 10 seconds , it will reset. did that it powered up . but the depth readings were way off. the depth was reading 32 ft. and the prop was chewing mud. can anyone say what might be wrong with it? is it time to replace? the puck is inside in the keel and will probably have to remove the gas tank to replace it. boat is a nitro 160 about a 95 and still in great shape.