"burned" spot Raymarine radar screen
Yesterday I was checking on the boat at her slip. I turned on the electronics to be sure they were ok.Tthe lower helm has a monochrome Raymarine RL 70 radar/gps/chartplotter, in the center of the screen there appeared to be a "burned" spot. The radar image came on and was normal on the outer edges but showed a reversed (like a film negative) image in the burned area. It was ok a couple of weeks ago when I tried it last. I didn't have a chance to check the flybridge unit also Raymarine 70 but color display. This is old stuff, probably 2003 original supply with the boat and I have been thinking of changing it out before too long but it has all worked fine. I am curious what could have caused it? Any ideas, I am quite sure there have been no close lightning strikes, I didn't try the VHF but the stereo works fine, same for fridge, lights, etc.
Thanks for any ideas!