Driver board transistors that look stuck on in a test fixture
On a test fixture Q57, Q61 and Q63 (2N3055 pre-drivers) and Q49-Q52 sit on, and Q13-Q17 are often pre-drivers whose tabs do nothing when grounded. Don't condemn them for that; Q13-Q17 can be checked in lamp test 16, which fires the coils they pre-drive.
Systems
Related tips
- Test the driver transistors while the board is out for the ground mod
- What the System 80 driver board transistors drive
- System 80 driver board transistor types
- Relay and coin counter transistors on the driver board
- Some 80B driver boards use the coin counter transistors
- Diode-test the driver board MPS-U45 and MPS-A13 transistors
- A meter test of a transistor is not conclusive
- Diode-test a driver board 2N6043
Source: Repairing & Upgrading Gottlieb System 80 Pinballs from 1980 to 1989, Part One, Clay Harrell (pinrepair.com)