Specification for replacement Sega opto LEDs

The emitters fail most. A replacement should be a T-1 3/4 (5 mm) red LED with a clear lens, about 644 nm ("ultra red"), roughly 1.7 V typical and 2.5 V maximum forward voltage, 20 mA maximum, around 3000 mcd and a narrow 10 to 12 degree beam. "Super red" 630 nm parts do not work, because the receiver responds only over a narrow wavelength band.

Systems

• Data East/Sega CPU Version 3b

Related tips

• How the Sega opto receiver works
• Which Sega games use optical switches
• How Sega optical switches behave
• Ball trough optos work intermittently

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