crunch gpx2200.2d

iam struggling a bit with a amp that power up but gate pads on lo side i think look like this.
481009364_1446135460096123_7609014895288806074_n.jpg

high side
479855780_620087980646295_6564280958860200682_n.jpg

when removing mosfets, i have sine wave on low side gate which i believe is quite wrong. what could be the cause of the sine wave or noise directly on the gate pad?

below shows waveform on gatepad with 100hz on rca
479716690_490132037489675_7973500526694866707_n.jpg