texasmame
Well-known member
Just for future reference here for someone hopefully. . .
Had a Nintendo monitor with amazingly loud hum and high pitch squeal. Touching/moving the volume pot seemed to change it, so swapped out pots. No change.
Then noticed that if I held the pot the noise would go away. Not a grounding issue - all checked out as grounded properly.
Looked at the traces on the audio board and followed out from the volume pot, replacing caps as I went. C374, which looked fine from above, was rotted out on the bottom. Replaced it and no more squeal and loud, loud buzz.
Well, now just have the very low "normal" Nintendo speaker buzz, that is. 
Had a Nintendo monitor with amazingly loud hum and high pitch squeal. Touching/moving the volume pot seemed to change it, so swapped out pots. No change.
Then noticed that if I held the pot the noise would go away. Not a grounding issue - all checked out as grounded properly.
Looked at the traces on the audio board and followed out from the volume pot, replacing caps as I went. C374, which looked fine from above, was rotted out on the bottom. Replaced it and no more squeal and loud, loud buzz.
