Anh
Naim ghetto blaster
I'm not suggesting that an unskilled person attempts to repair them, and certainly not the mains sections. I'm saying that a competent repair technician can repair them, and for an awful lot less than £300. But do carry on believing that Naim can only be dealer serviced if you wish.
You are missing the the point. Most (not all) Naim equipment is sought after and command high prices in the used market, and the expectation is if any servicing or repairs was done, it's not good enough for any qualified technician or an experienced DIY'er who argues on a forum in his spare time, it would have to be from the vendor itself.
Dont take my word for it, try putting a Naim olive or CB era pre or power amp on for sale at the going rate and you will understand.