Diode-test readings for TIP36c, 2N4401 and TIP42 transistors
TIP36c (PPB board): red probe on centre leg or tab, black on each outer leg, expect 0.4-0.6 V. 2N4401 (no tab): red on the centre leg, black on each outer leg, 0.4-0.6 V. TIP42 lamp column driver: facing the part, black on the left (base) leg, red on the centre and then right leg, 0.4-0.6 V. A reading near zero means a short, the usual way these fail.
Systems
Related tips
- 50 V coils use PPB TIP36c transistors, pre-driven from the CPU board
- Solenoid driver transistor positions on the CPU and PPB boards
- Lamp and switch matrix transistor positions on the CPU board
- Random coils fire instead of flashers with a new driver board: relay has the wrong coil
- MRB and PPB playfield power boards
- Three-stage drive for 50 V coils
- What the PPB/MRB board carries
- Check PPB solder joints: the board runs hot
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)