Mandatory 80/80A power supply rebuild

Steps

• Replace R3 with a 12k 1/2 W resistor (it often fails).
• Replace R10 with 680 ohm 1/2 W to take load off CR7.
• Replace CR7 with a 1N4738A even if it looks fine.
• Reflow every header pin, any short-trimmed lead and the large rivet holes Q3's legs pass through.
• On the solder side, add an 18-gauge jumper linking the ground trace with the lower mounting screw hole.
• Solder clipped resistor leads into the GND, +5, +8, +42 and +60 test points so they can be probed with the board mounted.
• Check the other resistors are in tolerance.
• Swap the round pins at J2 and J3 for Molex .156" square header pins (26-48-1125), and refit the 6-pin (J2) and 7-pin (J3) mating plugs with new 09-50-3121 housings and 08-52-0113 Trifurcon pins.

Systems

• Gottlieb System 80
• Gottlieb System 80A

Related tips

• Parts for the 80/80A power supply rebuild
• Reassemble and set up the 80/80A power supply
• Bench-test an 80/80A power supply in the game, part 1
• Bench-test an 80/80A power supply in the game, part 2
• 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)