Hum from a Golden Tube SE-40 !

I get a strong hum from my brand new SE-40 power amp, new tubes, factory biased. It's not the preamp, not the power cord, not the ac power. What could be the problem? Thanks a Lot.
sorry i dont know your soloution but just thought I would drop a line as i am a fellow se 40 owner i sugest you call the tech line or contact your dealer though i think solo electronics killed this line ? when retubing stick to sov.5881
Try turning your IEC connector around backwards when you plug it into the outlet, FOR EITHER THE PREAMP OR POWER AMP. Just do one of them.