Brightening a dim Futaba display with a 9 V battery

Steps

• Game off. Unplug the display's edge connector; the display can stay in the backbox.
• Clip a 9 V battery to the two outermost pins of the display glass (the filament ends, normally fed with about 5 V). Polarity does not matter.
• Leave it for a minute or two. The fine horizontal wires inside should warm to a faint glow; if they glow bright, the voltage is too high.
• Remove the clips and refit the connector.
• Use 6 to 12 V on six-digit displays but never more than 6 to 9 V on the small four-digit credit display, whose filaments are shorter.

Systems

• Gottlieb System 80
• Gottlieb System 80A

Related tips

• Gottlieb Futaba displays run on low voltage
• Display fault: board or display?
• Restoring brightness on 4, 6 and 7 digit display boards
• Guarding the fill tip on the back of a score display
• Missing segment on one or more score displays
• Missing digit on one or more score displays
• Gottlieb System 80: bottom segment missing on one display that follows it: replace Z1
• Display chips on the CPU board fail after swapping displays

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