The score displays flash and seem to roll or scroll in real life, not only on a phone video.

Score displays flicker and seem to scroll: weak high voltage, power board replaced

Cause: A failing display high-voltage supply on the power board; members pointed at the HV section and its filter capacitor.

Checks

• Make sure the flicker is visible by eye; phone cameras can make healthy displays appear to scroll.
• Measure the display high voltage at the power board and compare it with the manual.

Fix

• Repair the high-voltage section of the power board (filter capacitor and regulator parts) or replace the power board; here a replacement board cured it.

The display supply runs at well over 100 V DC and its capacitors hold a charge after power-off. Unplug the game and let the supply discharge before touching it.

Systems

• Bally MPU AS-2518-35

Games

• Cybernaut

Related tips

• One display digit glitches and the fault follows the display: bad resistors
• F2 blown, no display high voltage at TP2
• Capacitor C26 holds the display high voltage after power-off
• Flickering score displays
• High-voltage score displays flicker: reflow the cracked joints at the display connector
• Set the display high voltage to about 170 V
• Power up and set a rebuilt high-voltage section
• Displays strobe on early Bally SS: check the J3 ground pin for the HV circuit

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