What the A3 driver board drives

The driver board runs the lamp strobes and returns, the switch strobes and 32 solenoid outputs: 12N10L or IRL530 logic-level MosFETs fed from 74HC273 latches. Only 29 are free for the playfield, since Sol.30 and Sol.31 drive the tilt and game-over relays and most games give one to the backbox GI relay.

Systems

• Gottlieb System 3

Related tips

• Spare MosFETs for the driver boards
• Logic chips worth stocking
• Cue Ball Wizard: coils holding on weakly (BUZ72L MosFETs)
• Only logic-level (L) MosFETs work on the driver board
• Logic-level MOSFET equivalents: 12N10L, 20N10L, 22NE10L, IRL530, IRL540
• Last Action Hero / Guns N' Roses: magnet dead or locked on
• Diode-testing the 12N10L/IRL530 MosFETs
• Coil MosFET ratings and substitutes

Source: Repairing Gottlieb System 3 Electronic Pinball Games from 1989 to 1996, Clay Harrell (pinrepair.com)