Removing and/or replacing the keybed on the Sequential Prophet X synthesizer is a relatively simple process involving nothing more than a screwdriver.
***Thanks to Tom Fabinski for his keybed sacrifices and sharing the info and images for this post!
To start, unplug all power/audio/MIDI/USB cables
Instructions for replacing the key bed are as follows.
Unscrew the screws in the wood ends (see WoodRightSide.jpg and WoodLeftSide.jpg above)
Flip the instrument over and place it face down on a soft material.
Unscrew the two screws which hold the wheel assembly to the bottom metal work (see WheelToMetalScrews.jpg above)
Flip the instrument back over and remove the screws in the sides of the metal housing (see ScrewsRightSide.jpg and ScrewLeftSide.jpg above)
The front panel can now be opened, it is hinged at its rear.
Remove the key bed connectors and aftertouch cable connector from the main PC board (see MainBoard.jpg above, the cables outlined in red)
Close the front panel and flip the instrument face down again.
Remove the 10 screws which hold the key bed to the bottom metal work (see KeybedScrews.jpg above)
While holding the front panel closed, and the key bed to the bottom metal work, carefully flip the instrument front side up. Open the front panel, and remove the key bed.
Remove the aftertouch extension cable from the old key bed to install on the new key bed. It is taped in place.
Install the new key bed and reassemble the synth in the reverse order of disassembly. Take care when re-installing the key bed screws as they can strip the key bed standoffs if they are overly tightened.
IMPORTANT: The keybed standoffs are plastic. To avoid over-tightening and stripping standoffs when installing the keybed, DO NOT use an electric or powered screwdriver.