Steering Fet Burned

[Hemikid]

I recently purchased a revell rpmz for a cheap electronics upgrade for my xmods. I installed the rpmz electronics into my evo and drove it around my driveway for close to a half hour before it suddenly stopped. I picked it up only to see smoke coming from the body. When I took the body off the steering fet had a burned and ruined my electronics. My xmods is stock aside from the rpmz electronics, motor, and servo motor. Why would this happen?

[xmodzracer]

Possible cross wiring and or bad soldering?