My 390 has fallen off my bike at high speed twice. The first time it suffered just a scuff. The second time it got run over by an SUV on the first day of a 7 day trip to the Smokies. I had turned back to retrieve it and got to it just in time to watch the car's tire roll over it. It would power on but the screen was cracked and just showed a blank white screen.
I sent it to Short Tronics, Inc in Mankata, MN. The owner, Chris Short repaired it and returned to me in 3 days for $90.00. It powered right up and the voice said "Please drive to hilighted route" ready to resume out trip!
Although the glass screen is a liitle fragile, the rest of the unit is amazingly durable.