Which driver transistor fires which coil

All 2N6043: Q25 (far right) knocker; Q26, Q27, Q28 the 10, 100 and 1000 point chimes or sounds; Q32 outhole; Q31 coil 6 and Q30 coil 7 (game specific). Coil 8 uses an MPS-U45 at Q29 driving the 2N3055 at Q45, often for a drop target bank. CPU buffers: Q25 from Z6 pin 3/4 (A1J5-11), Q26 Z6 5/6 (J5-10), Q27 Z6 9/8 (J5-7), Q28 Z6 11/10 (J5-8), Q32 Z6 1/2 (J5-12), Q31 Z6 13/12 (J5-9), Q30 Z7 1/2 (J5-1), Q29 Z7 3/4 (J5-2).

Systems

• Gottlieb System 1

Related tips

• How many coils the driver board can fire
• Testing the 2N6043 coil drivers
• Testing MPS-A13 and MPS-U45 driver transistors
• Early driver boards lack isolation diodes
• Spare transistors for System 1 boards
• Meter transistor tests are not conclusive
• Diode test of driver board 74175 chips
• Testing the Q45 2N3055 and its resistor

Source: Gottlieb System 1 Pinball Repair from 1977 to 1980, Clay Harrell (pinrepair.com)