Behringer B212D makes pop noise, replacement PCB input board.

Hello, I had a bad PCB input board on my Behringer B212D

because the low eq knob was bad.  I have a new replacement board but when I plug it in, the board’s power light doesn’t light up, and when I turn on the speaker it makes a “pop” noise and then I hear a hum in the speaker. Also if I turn any of the 3 knobs on the board it makes a loud “pop” noise as well.  Please help!