B+K service near Tyler,Tx or Dallas,Tx

I purchased a Reference 200.5 series 2 amp, all channels good but the middle one. Heard a slight hum, smoked my Paradigm Studio CC . Checked all wires/ all good. Checked internals of amp and all looked brand new, no scorch marks at all, fuses all look good. Previous owner used the XLR inputs, I have to use the RCA's for inputs off my Onkyo 806. Any suggestions to check it further? Or where I could take it to to have it checked/fixed? I live in Tyler, Tx two hours east of Dallas/FortWorth area.