Red Drum

I have Rock Band 2 and after using for some time of a capital in the red drum pad. How do I remove this franchise?

I played drums with Rock Band 2 and after some time, has formed a lump in my red carpet drum. Has this happened before? Can I fix this package? This battery is only half a year.

Squishy is the mass? If so, it might be an air bubble of air in the drum is a little ... Although it is not sure that I do not know what it's like a franchise.

Red Drum