Chime coils used with System 1 must be 12 ohms or more
Every System 1 game can run a chime box instead of a sound board. Use chime coils of at least 12 ohms, or driver transistors Q26-Q28 will burn out. 50 V chime coils from another maker are fine, since their resistance is higher. Fit a 1N4004 across each chime coil, band to the power lug.
Systems
Related tips
- Early driver boards lack isolation diodes
- Testing a coil diode
- Testing the diode on a coil
- Which way a coil diode goes
- Which way a coil diode goes
- What the coil diode does and how a bad one shows up
- Testing a coil diode on the driver board
- Testing the diodes on a flipper coil
Source: Gottlieb System 1 Pinball Repair from 1977 to 1980, Clay Harrell (pinrepair.com)