Later System 11 moved relay and diode boards to the backbox
The first bank-select games used a bank select relay board and a diode board under the playfield. Later games moved these, the 50 V drivers and all the coil fuses onto the auxiliary power driver board, so only flipper coils still carry diodes.
Systems
Related tips
- Where the coil diodes are on System 11
- How the System 11 A/C bank select works
- How System 11 A/C switched solenoids work
- Which transistor drives the A/C select relay
- Testing coil diodes on the auxiliary power driver board
- Whole groups of coils or all flashers dead: A/C select relay stuck
- A/C select relay fails: welded contacts or cracked joints
- C-bank coil or flasher not working
Source: Pinball Machines: How They Work & Troubleshooting, Norbert Snicer