Never buy used amps from friends withouth hearing them brother. It will cost you more to get it serviced than it's worth. Alpine charges out the ASS for their service. I was gonna get my headunit looked at but they wanted $300...fuck that. I'll just ride this one into the ground.
Edit: The MRV-F353 series is Very old. I haven't seen that series amp in 4 years. I think you got screwed buddy. Hate to tell ya