I bought partially faulty Naim Unitiserve yesterday. At the price I payed, it would be worth sending back to Naim to repair. The fault symptoms made me think the CMOS battery had failed which is common for age. Upon collecting, the seller informed me that they had changed the battery but made no difference. Upon inspection, I found the CMOS battery had been fitted the wrong way round. Suffice to say, it’s now working perfectly.