Kenwood KAC-X1200M output stage burnt out

hello again friends, this time I come to ask for your support to solve a problem with a kenwood kac-x1200m amplifier, which with any load, blows the output fets, at idle the waves and output signal look good after of the coils, but when I start to give more volume it cuts off as if it were protected and returns repeatedly until it reaches the point that it flies 1 or 2 fets from the output stage, I do not find any damage, only the damaged fets, I will check one by one of the transistors that make up the pulsation towards the greetings output fets.