Did you ever get anywhere with a repair? I'm in the UK and was 18 months into a Richer Sounds 5 year extended warranty on a 751R. My 751 started popping fuses in the mains plug upon startup, and Cambridge Audio/Richer Sounds refused to spend the money buying in the parts they would need to make the repair. Long story short, after some negotiation (I did have a 5 year warranty after all), I ended up upgrading to a Yamaha CXA5100 (more money but paid dealer cost price, which was a pretty nice deal
), and I am really happy that I did. I was only using my 751 as a pre-pro anyway, but I wasn't expecting the Yam to be such as step up, as the 751 sounded excellent! I still have another 551 which I used whilst the 751 was away (until the 5100 replaced it), and that too has a great sound, but the CA products do seem quirky (fussy about connectivity), they sound great, but are not that reliable, and it would seem, when they fail, you may not get a repair. I still plan to use the 551 in another room in the future, fingers crossed that that doesn't go pop either!
It's a shame as I loved my CAs, but I won't be buying any more (though the new CX range they removed the pre-outs, so they IMO shot themselves in the foot there, which means people like me no longer could use their products, even if we wanted to...)