This is Xylobot (fixed October 2013) Page.
We'll list some issues on this page and code referenced to the w drive.
The Mystery of the Extra Perfboard under the keys¶
If you notice that there is an extra perfboard under the keys of xylobot, it's because the MOSFET on the E flat key is blown. We made a new circuit for that specific key. However we placed one of the diodes the wrong way round across the solenoid, so it created a short circuit, so we cut that diode and added a new one. We'll post a circuit diagram of the solenoid, diode and MOSFET in this page... hopefully. That should resolve this problem.