You definitely need to send the C80 back to Raymarine. As long as you can be without it for a few weeks, just send it with a good description of the problem and all of your contact info. Include a request to have them contact you with cost before performing the work. Then you can decide what to do. I think you will find it to cost less than you might think.

The only other way would be to change the PSU board in the unit. The connector back plane is connected to this board.I am a authorized Raymarine repairer. I could drop ship you the board from Raymarine and email you an instruction manual on how to change it.I am not located in the US so shipping the unit to me for repair becomes expensive.You can also check with your dealer in Seattle first but I do not think that he can buy the board from Raymarine. Raymarine policy on repairing product is different from country to country. We are on the other side of the world so Raymarine allows us to repair there product as it is to costly to ship it all back to there repair facility in the states or the UK.If your unit is still under factory warranty then if you open it it will void the warranty.So then you would have to send it to Raymarine. With a diagram if you are natural a technical person you will not have a problem changing the board.If you are technically challenged I would say send it to Raymarine. Hope this helps.