On one display, the 'h' segment lights whenever the middle 'g' segment lights. The fault moves with the display, and the driver chip tests normally.

Two segments always light together on one display: bad display glass

Cause: An internal fault in the display glass itself.

Checks

• Test the segment driver chip (Z1) as described for these displays.
• Lift the driver pin for the extra segment; if the segment still lights, the glass is bad.

Fix

• Replace the display glass (or the display).

Gottlieb displays run on high voltage; work on them unplugged.

Systems

• Gottlieb System 80

Games

• Pink Panther

Related tips

• A display segment or digit is always on or always off
• Gottlieb System 80: bottom segment missing on one display that follows it: replace Z1
• Display fault: board or display?
• Telling a bad display driver from a bad display tube
• Replacing a display glass tube
• Display chips on the CPU board fail after swapping displays
• How the System 80 fluorescent displays light
• Meter check of the UDN6118 display drivers

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