Replace a score display glass

Steps

• Cut the old glass's pins (the board is what you are saving), then heat each pin and pull it out with pliers and clear the holes with a solder sucker.
• If the lower bracket was taken off for cleaning, put it back now.
• Straighten the new glass's pins and feed them in from one end, then bend each pin into a strain-relief curve so heating does not crack the glass at the seals.
• Check alignment against another display with the plastic bracket fitted, clamp gently (wooden clothes pins work) and tack the end pins; recheck alignment.
• Solder all pins on both sides, check for bridges, trim the leads and check again.
• Put a small dab of silicone at each end of the glass (do not glue it fully) and a large dab over the glass tip to protect it; let it cure overnight.

Systems

• Bally MPU AS-2518-17
• Bally MPU AS-2518-35
• Stern MPU-100
• Stern MPU-200

Related tips

• Flickering score displays
• Bally and Stern score display boards
• How a Bally display board drives its glass
• One digit missing on a score display
• Score display J1 to MPU J1 connections
• Score display digit parts by position
• Score displays dim
• First checks before repairing Bally score displays

Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Three, Clay Harrell (pinrepair.com)