Does anyone know of anyone capable of repairing an RNS-E main unit?

I've have problems with it reading the NAV disk, which has become frustrating to the point that it's useless. Further, the screen blacked out tonight.

Any recommendations?

I forgot to mention. Within North America. It would seem that there are MANY repair facilities in the UK, but I'm looking for something in the lower 48, if possible.

Thanks,

CW