Fixing an NAD 216 making chirpy sounds

PMedland

Member
2013-03-16 3:48 pm
Someone spilt punch all over my NAD 216 at a party, and after replacing the blown internal fuse, it powers on and works, but one channel is making constant, weird, low-level chirpy sounds. Does anyone know what's likely to be causing this, and which components I should start with replacing?

Thanks.
 

Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
The proper way to clean a PCB is quite difficult. Unless you remove and wash the board thoroughly in a ultrasonic bath or scrub with a long bristle brush using solvent/water mix with a bit of detergent detergent added, you won't remove the sticky, sugary residue.

This drops into the through-hole recesses and remains - maybe benign, maybe it makes a resistive path where you don't want it and that causes havoc at signal level. Maybe it just starts corrosion and your PCB comes out in verdigris.

I use a blend of meths and water to clean boards but plain hot tap water should be OK provided you don't allow unsealed components like large output relays to get wet. Dry the board thoroughly in a warm oven but don't let it get over 60C.

You can make a half-hearted effort with a paper towel but you already know the result. Clean it properly and you might not have the problem.
 
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Hi, you mentioned that it only does it on one channel. I believe the 216 has one PCB per channel right? You can remove both boards, clean them out as much as you can and then if the problem still persists, if you're handy with a multimeter you can measure both boards, side by side and see where your problem lies. Just trace to which output which board goes to and you'll get which is the good board and which the bad. Good luck :)