I was checking out my radar and it seemed "frozen". After some of my favorite swears, I found some fresh water inside of the dome. It is a Garmin 19" dome bought in 2008. I got it working, but my question is; should I spray it with WD40? The Garmin people say send it back to them with $400. No answer about the WD40. Does anyone have experience spraying WD40 on electronics such as the inside of a radar? Also where did the water come from? The dome is not cracked, the gasket looks very good, and the boat was stored inside all winter. I noticed some green scum with the water like it had evaporated in the past.

Get Electronics Spray Cleaner

2nd that......... it's made for the job

The dome should have a drain to allow any water that is inside from condensation from temperature changes. Make sure the drain isn't clogged or was obstructed when unit was installed.

What both of them said, electronics cleaner. WD40 will just gum the whole thing.