Bed MOSFET melting adjacent connector (no replies)

So I recently blew out the Melzi board in my Wanhao i3. I decided to go RAMPS to have a more reliable printer.

Got a RAMPS off eBay and paired it to a Mega clone I already had. Got the motors to move and home without any issues.

Hit the bed with a heat command to make sure everything looks good. Within 10 seconds or so I heard sizzling and saw smoke, so I killed power.

Looks like the heat bed MOSFET got hot and started melting the D8, D9, and D10 connector.

Pulled everything apart and checked all connectors, checked resistance on the bed, everything appeared good.

Put it back together and tried again with same results, MOSFET is getting hot fast.

The MOSFET is a P55NF06. I have read that these are not ideal but they are used successfully.

Is this just a crappy MOSFET or should this work in theory? The heated bed is 200x200 so it should not be drawing a huge amount of amps. I do not have a way currently to measure amp draw on the bed but this should be around 11 amps.

I have a external MOSFET unit on its way from China, but I am concerned that even with that, something is screwed up with my board.