I think it was this thread earlier, but Bacons/Annapolis earlier had 2 or 3 C80, some with all additions. I'm on my second C80. the first having failed as yours did. Keep us posted on your replair, please.
So here's the C80 report. I sent it off to Seawire Marine on Monday, June 1. They received it mid-day on June 3. They repaired it on Monday, June 8 for $300 + $35 shipping, and shipped it back to me by UPS ground. I received it Thursday, June 11th in late afternoon, and today I plugged it back in to the boat. Everything works as new. It even remembered my old waypoints (for whatever reasons: not claiming this is unusual). So basically, I paid $50 for 2-day UPS to get it down there quickly, and $335 to get it fixed ("Raymarine Classic Image Repair w/Software Update" and 1 year warrantee) and shipped back. I'm very happy with this repair: much better than 1-2K for a new plotter plus installation. I'm not aware of another place in the US that does this type of repair, but if any of you are, please chime in and let us know. In any case, I can strongly recommend Seawire for Raymarine repairs.