What the System 80 driver board transistors drive
Only six transistors are dedicated solenoid drivers (solenoids 1, 2, 5, 6, 8, 9): 2N3055s at Q58, Q62 and Q64 and 2N6043s at Q53, Q59 and Q60. The rest are MPS-U45s and MPS-A13s that drive CPU lamps directly (there is no lamp matrix); an MPS-A13 handles one lamp and an MPS-U45 two. Extra coils use under-playfield 2N5875 transistors pre-driven by MPS-U45/MPS-A13 lamp outputs. Pops need no driver board transistor because they have their own boards.
Systems
Related tips
- System 80 driver board transistor types
- Test the driver transistors while the board is out for the ground mod
- One driver board fits every System 80, 80A and 80B game
- Some 80B driver boards use the coin counter transistors
- Test driver board outputs by grounding transistor tabs
- Driver board transistors that look stuck on in a test fixture
- Diode-test the driver board MPS-U45 and MPS-A13 transistors
- A meter test of a transistor is not conclusive
Source: Repairing & Upgrading Gottlieb System 80 Pinballs from 1980 to 1989, Part One, Clay Harrell (pinrepair.com)