I have a 2001, 4.4 X5. The radio and CD player went dead. No sound at all. The MID showed the radio stations and the tracks changed on the display when I had it in the CD mode. I surmized that the amp had gone bad. I bought one off e-bay. I installed it and it palys for about 60 seconds and then goes dead. If I turn the radio off and immediately back on it will play again for about 60 seconds. The amp is DSP. Can anyone point me in the right direction.