I've got a very nice example of this amplifier here but there is no sound output on either aux or video channels. Every other channel plays great but nothing from aux or video.
Looking at the schematic, I see no reason why these shouldn't be working while the rest are.
Has anybody had an issue similar to this with this model or similar?
Looking at the schematic, I see no reason why these shouldn't be working while the rest are.
Has anybody had an issue similar to this with this model or similar?
Input switching is just relays. Use a DVM to check for the proper coil DC voltages when selected.
https://www.hifiengine.com/manual_library/nad/c350.shtml
https://www.hifiengine.com/manual_library/nad/c350.shtml
It seems that the relays for these 2 inputs are temperamental. I can't always hear them switch as I go through the sources via the selector switches on the front panel. Is it advisable to clean these HRS2H-S-DC12V relays and, if so, what's the best method? Do the covers come off them easily?
First make sure their coils are getting the proper DC voltage when they are actuated.
If they are, then I would just replace the bad relays.
If they are, then I would just replace the bad relays.
Well after swapping one of the questionable relays with one from a working input, it appears that just the 2 for aux and video have damaged coils while all others are fine. There is some action going on inside the bad ones but the contacts are not closing at all. New Multicomp MC25119 relays are on the way which will hopefully last a bit longer than the original Huigang ones, though I won't be replacing the remaining working relays on this occasion.
Voltage inconsistencies were measured prior to the swapping of the relays and that inconsistency has moved with the relay after swap, hence I know the coils are the problem and not the contacts.
It's a mystery how this has happened in this little used example given I can't find any other reports online of these relays failing. I suppose that's equally because it's an easy fault to identify and that nobody is surprised by the failure of a 'Huigang' relay...
It's a mystery how this has happened in this little used example given I can't find any other reports online of these relays failing. I suppose that's equally because it's an easy fault to identify and that nobody is surprised by the failure of a 'Huigang' relay...