You can probably test the X401 by just comparing it to the other one just like it in the same section, with it still on the board. Measure between base and collector, then base and emitter. Compare it to the transistor on the other heat sink, your numbers should be pretty similar.
The resistor is like FR401 or something like that, it's right beside that area, and is a white resistor that sticks up off the board pretty high. You'll recognize it because it'll be burnt all to hell and have crappy looking legs and solder joints.