Sega/Stern WhiteStar I/O Driver Board Weird Signal Discontinuity Causes Lamp Matrix Issue

Chris Hibler diagnoses a Sega/Stern WhiteStar I/O driver board (Rev G) with a lamp matrix fault, using a custom tester and archived Stern schematics to trace the problem to a hairline fracture in a PCB trace carrying data line 5. He repairs the trace with a jumper wire, conformal coats it, and also replaces the power header, tightens the LM338 regulator, and swaps a flipper FET for a beefier P40NF10L. He then verifies the lamp matrix and coil/flasher circuits using a Harley-Davidson ROM.