Recommended extras for the 80/80A power supply

Steps

• Replace the 500 ohm trim pot with a good-quality sealed 470 ohm pot; the original gets dirty and lets +5 V wander.
• Fit a 1N4746 18 V zener at CR6.
• Replace the two LEDs, which dim and draw extra current with age; use orange or yellow (not green or blue) so a changed board is easy to spot.
• Socket the 723 regulator chip, which often fails.

Systems

• Gottlieb System 80
• Gottlieb System 80A

Related tips

• Bench-test an 80/80A power supply in the game, part 1
• Bench-test an 80/80A power supply in the game, part 2
• Parts for the 80/80A power supply rebuild
• Test and remove the 80/80A power supply's big transistor
• Original 80/80A power supply design overheats CR7
• 80/80A power supply has 12 V but no +5 V
• Which System 80 power supply boards are interchangeable
• Tie the 80/80A power supply logic ground to its heat sink plate

Source: Repairing & Upgrading Gottlieb System 80 Pinballs from 1980 to 1989, Part One, Clay Harrell (pinrepair.com)