What would cause me to loose a channel?

I have a fairly new Naim CDX2 CD player that I really enjoy. This morning when I went to play a disk, nothing from the left channel. Worked fine last night and every day since I bought it new in November. There was no funny noise, pop, smoke or any indication that something was wrong. The right channel plays beautifully. I changed interconnects, pre-amps, etc and it is the left channel. It is going in on Wed. for service, I am just wondering what part of a cd would fail so completely so suddenly. Thanks.
Just for the fun of it, (if you haven't already) try unplugging it from the wall and starting it up again. I have a Naim player and had BOTH channels stop working and after I reset it all was well. Good luck!
I did that. I also reprogramed it from rca to din and back to rca. Swapped cables from phono to cd, phono worked great with the cd cables and cd still had left channel out, Changed power cords, changed pre-amps all consistent left channel out on cd. On a seperate note my audio dealer loaned me a VTL 6.5 line stage to see if my Belles 21A is at fault. Wow, the VTL is really nice and I would like to have one but I am surprised at how nice the belles is. Though I would love to have the VTL I could easily live with the belles, it has NOS RCA 5814A's that were the best Vintage Tubes had. But, need to get my CDP up and running before any new upgrades. Though I love my vinyl I am already missing my digital source. Thanks for your suggestion anyway.