Lamp and switch matrix size and drivers

There are twelve strobe lines shared by the lamp and switch matrices, and eight returns for each, giving 96 lamps and 96 switches. Strobes are 12P06 MosFETs driven through 74HC164 and 7406 chips; lamp returns are 12N10L MosFETs driven through 74HC273s.

Systems

• Gottlieb System 3

Related tips

• Proving the driver board's switch strobes
• A whole row of eight switches dead
• What the A3 driver board drives
• Spare MosFETs for the driver boards
• Only logic-level (L) MosFETs work on the driver board
• Lighting a whole lamp column by hand
• Coil or flasher on as soon as the game powers up
• Logic chips worth stocking

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