JL Audio E1800 (no sound)

Well i dont know what happened. The amp was just give to me. The only thing i have is a multimeter and a small test bench . I know that i dont have the setup or equipment to properly work on amplifiers, i just thought maybe id get lucky and it would be something fairly simple and i could replace a couple parts and fix it. I have been fortunate enough to be able to do some minor repairs on a few different amps, xbox, laptop, and a couple iphones. Any way im just trying to use this as a learning project. I understand if you dont want to talk with me about this.