While performing a recent upgrade to add a heated build plate to my trusty Replicator 2 I made an (almost) fatal mistake: I put the new 9amp power supply plug in upside down! Needless to say, the sound and smell that came out of the printer was excruciating. While this was a dope-slap moment on my part – I partly blame MakerBot for not properly keying their power supply plugs. I thought all was lost. Luckily, my retired electrical engineer of a father is much better with these types of issues. He talked me down and proceeded to prod the motherboard with his multi-meter. Since MakerBot closed-source their MightyBoard design a few years back there is no public schematic for this board. Never fear! My father was able to diagnose the problem and hack a solution. First, we were somewhat lucky in that the burned components were mostly on the BotStep daughter boards – which are cheap to replace. However, we were unable to get the 5V circuit to come back – so dad hacked up a separate power supply. Now my MakerBot has two plugs! Now I am struggling with getting the print head to home properly, but that is for a future post… here is a shot of the hacked board: