Today while listening to music I noticed that the sound in not coming from the right channel, first I thought may be it is in the track as mostly I play internet radio in the background. I tried all what I can do to check by resetting amplifier to factory settings, swapping the cables but no sound. However there is cracking sound from the right channel when switching the amplifier ON and OFF. Did any one had this kind of issue in the past? I have already contacted the dealer from whom I bought and even sent the email to the naim support team, I hope I get the new replacement as the unit is less than 5 months old. I hate to say that I have not a good experience with the NC. First NPX 300 and now 250. At least I am not worried as my investment is safe and naim has a very good track record of customers support.
Those - are the correct things to do.
Its for your Naim Dealer to address.
Speculation on here is not likely to fix it… 
Sorry to hear this, hope it’s fixed soon! What happened to NPX300?
There were two things, first was cosmetic as the LED was different from that of Nap 250. The led for nap 250 has a blueish tint and Led for NPX 300 is creamish may be due to different manufacturing batches. Second is technical as the unit does not stay in standby when switched off fully, it starts directly ON.
Oh dear.
Yes I think Elmarko had an issue with the right channel on his NC250 too.
It all worked through for him and I’m sure it will do for you, Naim are a decent company to deal with, but it’s just the inconvenience factor and reliability concern.
Hope you get it sorted soon.
Perhaps it’s the Ndx2 faulty relay? Have you another source to try?
I tried the nap 250 with nsc 222 at my friend’s place, same issue right channel not working but having weird noise while switching ON and OFF from the right channel. Now the NDX2 is connected to my SN3 and it’s working fine.
At least you have already the SN3 as interim. Hope your dealer will sort you quickly from that issue.
I had a NC250 with very loud transformer noise. The replacement had one channel with gross distortion, like a detuned radio. The third one seems good, so far, with much lower level of transformer noise. I’ve never had any trouble at all with Naim gear before, so while I’d like to think it’s just bad luck I’m a bit on edge with the whole experience.
I lost the right channel but it was static/humming coming out, not silence. Unit went to Montreal for repair. They were taking too long to get the part so they sent me a new unit. No issues so far.
My unit too is not completely silent on right channel there is a slight noise but loud crank when turning ON and OFF.
The noise was very noticeable with mine. It occurred in the middle of the night (units left powered up) and the noise was unaffected by the volume gain (ie constant).
I hope the issue gets resolved quickly, the unit is only 5 months old 
Mine was about 4 months. Hopefully you’re not in North America b/c they have a long queue of work. I was extraordinarily patient with them and in the end they opted to send me a new unit.
Hi BTN,
I’m afraid it’s difficult to say, other than hardware failure, as the NC 250 is quite a complex beast!
Regards
Neil.