You've likely blown your fuses on one side, remember you have two of them per side. Very easy to replace. I've owned a McCormack DNA amp for several years, and on rare occasion have had it happen.
First, look at the fuses. There are fuses inside for each channel. See if they are blown. Second, call SMC audio in California, they will give you all the info you need and will be able to repair the amp should it need it.
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