I have repaired this problem a couple of times in NAD units and each time it was either a bad capacitor on the board that is vertical right between the power transformer and the heat sink. I can not remember the value of the capacitor, but it was near the middle of the board it is on and had the top of the cap pushed out a little. Or it was cold solder connections on an IC on the digital board. It has been over a year since I did these repairs, so I can not be any more specific due to failing memory. To sum it up for you, you will need to have it serviced by a qualified service technician to have it solved unless you have some very good electronic repair skills. I am sorry I could not be more help, but since this is a very good unit, it would be well worth getting repaired, it is not a cheap-o unit. I have been repairing audio equipment for over 18 years and have gotten pretty good at it, so I am sure the problem you have is not a real major problem, but it really does require some service from somebody who knows what they are doing. You should not let anybody touch it unless they are well qualified, it normally ends up costing even more money for a repair after an unqualified person tries to do repairs that they know nothing about. It is very easy to cause further damage that can be avoided with proper service. sorry i went on so much about this, but I really like the NAD you have and I honestly think you would be better served to take it in for repair.
Answers & Comments
I have repaired this problem a couple of times in NAD units and each time it was either a bad capacitor on the board that is vertical right between the power transformer and the heat sink. I can not remember the value of the capacitor, but it was near the middle of the board it is on and had the top of the cap pushed out a little. Or it was cold solder connections on an IC on the digital board. It has been over a year since I did these repairs, so I can not be any more specific due to failing memory. To sum it up for you, you will need to have it serviced by a qualified service technician to have it solved unless you have some very good electronic repair skills. I am sorry I could not be more help, but since this is a very good unit, it would be well worth getting repaired, it is not a cheap-o unit. I have been repairing audio equipment for over 18 years and have gotten pretty good at it, so I am sure the problem you have is not a real major problem, but it really does require some service from somebody who knows what they are doing. You should not let anybody touch it unless they are well qualified, it normally ends up costing even more money for a repair after an unqualified person tries to do repairs that they know nothing about. It is very easy to cause further damage that can be avoided with proper service. sorry i went on so much about this, but I really like the NAD you have and I honestly think you would be better served to take it in for repair.
Dave