Gottlieb System 1 and System 80 power harnesses look alike: check before fitting

A replacement power harness for the MPU sold as System 1 (A1-J1 to A2-J2) may really be the System 80 version. The System 1 harness carries two supplies (+5 V and -12 V); the System 80/80A/80B one carries only +5 V and ground, has a different pinout, and its MPU plug is one position shorter, so it will not fit a System 1 MPU. Check the pinout against the schematic before using a new harness.

Systems

• Gottlieb System 1
• Gottlieb System 80
• Gottlieb System 80A
• Gottlieb System 80B

Related tips

• No sound though the sound board boots: 5 V reaching it is low, adjust the trim pot
• Gottlieb System 80: credit display stays dark: broken filament supply wire
• Wire gauges in System 80 harnesses
• Same digit wrong on the player 1 and 3 displays: failed Z17 on the MPU
• Haunted House and Black Hole fuse panel
• Gottlieb System 80 edge connector housings can be reused with crimp pins
• System 80 board "A" numbers
• Control board A1-J1 power connector

Source: Pinball Repair help group!! (Facebook group)