It looks like they have opted not to use the heated bed mosfet but instead use D10 to control a separate heated bed mosfet on its own board.. (probably to avoid issue with low quality mosfets and poor connector choices on the SL)
If it was me, I would take the wire that currently goes to d10 and solder it to the to the gate pin of the unused mosfet, this effectively moves it from D10 to D14
(this is the pin right above the label Q2 in this image
You can remove Q2 if you like, or leave it, it wont make any difference)
You then have to update your firmware with this new pin in your pins.h file.
Edited 2 time(s). Last edit at 01/01/2016 02:30AM by Dust.