P200 Subwoofer all quiet

Try taking tha cable out of the amplifier and touching it, this should create a low hum, as your body is sending throug a small current. if this works then you may have accidently switched the sub woffer on in the amplefier. if however you get nothing through the sub then you may have a dry joint in the solder, or the board may be dead. Other option, try an other cable. they also use lead based solder so they do get old.