I've had my 498 flush mounted (hardware and caulk) in my dash for about 2 years now, and never had a problem. We fished on a very VERY rough day a few weeks ago and lost GPS in the middle of the trip (the unit powered down and would not re-start). Ever since, I have not had a functional GPS.
If I unplug the two cords from the back (antenna and power) and then plug them back in... it will start up, but turns off after about 3-5 seconds. It may do this one or two more times and then it will not respond at all to me pressing the power button.
I'm hoping:
1) I do not need to send it in to the factory
2) I will not lose all my saved waypoints
Any advice before I pull it?