Hi all, I've had this issue off and on for a while. I don't know what causes it or makes it stop. Sometimes the number pad stops working and all the display lights (next to reverb, chorus, scale, etc.). I can still use the + and - buttons to move around but not the number pad. Sometimes this happens when using battery power and is resolved (at least momentarily) when plugged into power. Same issue still occurs sometimes even with new batteries or when plugged in. I got the keyboard about 9 months ago and have been using it actively for about 2 months.