Just a post that may help some one with a bad LEAR amp due to battery charger error or voltage surge. This was my situation and what worked for me on my 2001 X5S NON NAV with DSP. THe amp was fried due to garage error with a battery charger in boost mode. The radio worked and had all the features like it always did except it crackled and had no bass or sub working. I got a used numbers matching non nav amp to replace it. Nav and Non Nav is important when getting your replacement. I installed it and confirmed every ones posts that it will work for about thirty seconds and quit. It also did not have any of the EQ features. Your supposed to go to the dealer and have it programmed to your vehicle.

So here is a fix that worked for me. Remove the cover on the side of the amp that has just one connector on both the good and the bad amp. Remove the 7 screws that hold down the printed circuit board and lift it back by the edges carefully. There are two ribbon cables at the opposite end from the connector. Tip it out of the way and remove the tin tray that separates the two boards. You will see releases on the outer edges of each cable connector. Push them down to release the cables.

This is the board that does all the control and program information and chances are its good. The other board ( two connectors) is the actual amp which is probably bad. Take your original , one connector (programmed to your car) board and place it into your replacement amp and put it back together. Plug it in and it should work fine.

Saves the headache and cost of going to the dealer to get it programmed and its simple to do.