Power supply bring-up, step 3: displays

Steps

• Plug in power supply A2-P3 (display power). Optionally plug in CPU J2/J3 (displays) and J6 (slam and test switches, not needed after the slam mod).
• Power on and recheck the A2-P3 voltages; they should not move by more than about 5-15 percent.
• If they drop a lot, a display may be shorted: power off, unplug all displays, then add them back one at a time, checking voltage each time.
• Only plug or unplug displays with the power off.

The display supply runs at 60 to 69 volts; work on it with the game off and never plug or unplug display connectors with power on.

Systems

• Gottlieb System 1

Related tips

• Power supply bring-up, step 1: inputs
• Never plug displays with the power on
• How the Gottlieb fluorescent displays work
• Score displays flicker or go dim
• Which CPU chips run the displays
• Reviving a faded Futaba display
• Displays are scanned, not lit steadily
• System 1 and System 80 six-digit displays interchange

Source: Gottlieb System 1 Pinball Repair from 1977 to 1980, Clay Harrell (pinrepair.com)