Zener diodes D10 and D11 by DMD power supply revision

520-5047-00: D10 1N5379 (110 V), D11 1N4742 (12 V). Early -01 boards (Rev A, B) have no R17, with the 100 V 1N4764 at D10 going to ground and the 13 V 1N4743 at D11. Rev C -01 boards and all -02 boards add R17 and swap the two: 1N4743 at D10, 1N4764 at D11 going to ground. The -01 and -02 boards are interchangeable.

Systems

• Data East CPU Version 3
• Data East/Sega CPU Version 3b

Related tips

• DMD power supply 520-5047 revisions by game
• -125 V and -113 V read the same and the display is dark
• Small and medium DMD power supply CN5 pinout
• DMD shows lines or lights up fully, and no CPU lamps work
• Power supply board versions are not interchangeable
• Z1 on the power supply is a varistor, not a diac
• Power supply board versions and their +5 V filter capacitors
• Power supply CN1 pinout, pins 1-6

Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Three, Clay Harrell (pinrepair.com)