Rockford Fosgate 600a4

This amp will Power up and play clean audio for about a min then it will burn all 4 bias transistors Q105,205,305,405 ..

After it burns them I get full rail voltage measured directly across WA h speaker terminal for all 4 channels ..

I replaced them 2 times now and the amp will play clean audio after a min all 4 of them burn again so all 4 channels have excessive DC on the outputs ..

Everything tests good in each channel..

Any ideas on what I'm missing here ?