Step 3: Testing power transistors
The same process for testing a small bi-polar transistor can be used for testing large power transistors. The metal case is the collector. The two pins are a bit above the center of the transistor, as you can visualize here. The left pin is the base. The right pin is the emitter. Use a 100 ohm resistor to bias the transistor instead of a 470 ohm resistor.