You've upgraded to a new OS version and now some of the pads don't seem to work correctly any more. Symptoms might include some pads seeming louder than others, or a pad producing no sound whatsoever.
Sometimes during an update, the internal pad calibration data will be reset or lost. Recalibrating the pads will fix this problem.
- In GLOBAL mode, P0 Basic Setup, from the menu command button select Pads Calibration.
- Per the on-screen instructions, touch the center of all 8 trigger pads softly, then touch Done.
All the pads should now play normally.