Use TIP102 when replacing a TIP122

The TIP102 works the same as the TIP122 but is tougher; Williams used it on the later WPC boards. Replace failed TIP122 drivers with TIP102.

Systems

• Williams System 11
• Williams System 11A
• Williams System 11B
• Williams System 11C

Related tips

• Quick check of all TIP122/102 drivers before first power-on
• Lock diverter locks on at power-up and gets hot: shorted driver transistor Q22
• CPU and driver board transistors by position
• One pop bumper weak and sluggish though coil and switches are fine: replace Q77
• Replace failed TIP122 drivers with TIP102
• Quick test for shorted TIP122/TIP102 drivers
• Same coil driver transistor keeps blowing after replacement: counterfeit TIP102s
• Diode-test the TIP120/TIP102 and 2N4401

Source: Repairing Williams System 11 Pinball 1986 to 1990, Deel 1, Clay Harrell (pinrepair.com)