I have the exact same model of piano. I am able to get it fixed. It took me about 6 hours. The keys would not return to its up position after pressing on it. It turns out the white plastic that holding the weight of each key has expanded over time. The aluminum rod that goes through each weight is getting too tight for the weight to move (rotate) freely. Also, the expended white plastic is pushing against the side of the black case that holds the weight and the rod together. To fix the issue, I did the following: (1) Take the keyboard assembly out of the cabin. (2) Remove a black slotted case at the bottom side of the keyboard assembly that holds the weight and the aluminum rod. (I started from the right where the case holds only 4 keys.) In order to do that, remove the keys from the assembly first. (You have to first remove the screw, a metal plate, and a black thin plastic thing that holds the keys in the locked position at the back of the assembly, Then push the key toward the back of the assembly to...