this is definately a heat/humidity problem...why do marine
mfrs. color their products in a dark tone (not all---icom, for one)? this absorbs heat from the sun and causes condensation
build-up inside the unit. years ago, i had a garmin
75 handheld gps
that fogged constantly (in fla). i sent it back 4-5 times and it fogged instantly after turning it on (within an hour)..they even replaced the unit and the new one did the same...my new one doesn't do it but my hummingbird fish
finde just started to do it (after 15 yrs)... sheeeeesh, gremlins...