2004 A4 Blaupunkt Amp Pins
 

My '04 A4 Cabriolet has a Symphony Sound system and I suspect my amp is bad. It made a loud pop (in the speakers) and I lost all sound. I removed the amp and found that it's a Blaupunkt with the following two sets of numbers: "8H0 035 223" and "7 607 792 081". How can I determine if it REALLY IS bad?