Check PPB solder joints: the board runs hot
The MRB and PPB nicknames come from how hot they get, and the heat cracks solder joints, especially on the relay, resistors and connectors. Nothing removes the heat, so inspect and reflow these joints whenever the board is out.
Systems
Related tips
- MRB and PPB playfield power boards
- Solenoid driver transistor positions on the CPU and PPB boards
- 50 V coils use PPB TIP36c transistors, pre-driven from the CPU board
- Random coils fire instead of flashers with a new driver board: relay has the wrong coil
- Three-stage drive for 50 V coils
- How a coil or flasher is switched: PIA to TTL to pre-driver to driver
- Diode-test readings for TIP36c, 2N4401 and TIP42 transistors
- Replace the pre-driver along with a failed driver
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part One, Clay Harrell (pinrepair.com)