In addition, or after trying, @JayGilb 's suggestions, you could try a DC blocker on the power cord. Here is one, a search will likely turn up others: https://emotiva.com/collections/accessories/products/cmx-2Unfortunately mine has developed a humming/buzzing toroidal transformer. Anyone know what I can replace it with? I think the output is 95.6V (Red) and 19.6v (blue and green) and I couldn't find any transformers with that output.