After some research I finally have most of my first gen mpu9211 boards fixed. Various post pointed to adding a 10k resister to the aux sound board for reducing unbearable sound volume. The board was basically unusable new out of the box. The newer gen boards have a 2nd sound pot added below c112 on the mpu. I tried adding 10k to c112 and it works great. I also tried lower values but this was the winner. As others have stated, the single sound pot seems irrelevant since no difference in adjustment. However some said it needs to be turned bunches. I hooked a small flathead bit in my drill and went to town. I finally made a difference. This allowed me to balance out the sound. You may be missing half of your sounds like me because of one volume way to loud and the other way low. After 2 Years I’m ready to put this baby to good use. Now on to finding out the display is out on another nib 9211.

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