I have a roland Ep 9 digital piano and the problem was the keys were very hard to press whenever i started playing and there was a clicking noise while pressing them. These keys use grease to be played smoothly, so i decided to repair it and share it with you because I have heard that sharing is caring......
I hope i could do the justice to teach you how to disassemble and repair in detail.
Step 1: Unscrew the Back Cover of the Keyboard
Unscrew all the screws from the back side of the keyboard an keep all the screws in a bowl or something you find is safe for screws as you will need them while re-assembling.
Step 2: Lift the Cover Like This
Step 3: Now Unscrew the Highlighted Screw on Both Sides
Unscrew these screws on both sides and pull the Blind gently.
Step 4: Remove the Strips Carefully
Gently pull one end of the strip at a time and then second and remember the position of the strip ends.
Step 5: Unscrew the Keyboard
keyboard means here is not the piano itself it is the board where the keys are attached. This part can be separated as follows from the entire piano.
Step 6: Gently Push the Lock of the Keyboard With Your Thumb
Step 7: Unscrew the Pcb
unscrew the pcb and lift the rubber switches and chassis
Step 8: Remove the Key Stopper
there is a key stopper which has no screws but it uses double coated tape. Just remove it as in the image. And while reassembling use double coated tape and press it hard.
Step 9: Remove the Spring of the Keys
Carefully remove the springs of the keys as shown in the image use a tweezer to hold the spring and keep them in a secure box or whatever you find is safe so you don't lose it.
Step 10: Disassemble the Keys
Now Disassemble a white key and as shown in the image you will see old and sticky grease there which causes the trouble of clicking noise and hard to press keys. Remove the old grease with Isopropyl alcohol swabs which i used and apply new grease to make them work smoothly.
Step 11: Reassemble Every Thing
After applying the grease reassemble every thing from end to start and enjoy smooth piano playing.
I hope you will like it.