Intermittent faults on early boards (Haunted House and older).

Intermittent faults from cracked solder joints on early boards

Cause: At the factory component leads were cropped into the solder fillet, and double-sided boards were wave-soldered too cool, leaving plated-through holes (vias) empty, especially near the edge connectors.

Checks

• Look for joints that are puckered, cracked or open around the lead.
• Look for vias with missing or sunken solder.

Fix

• Reflow every suspect joint with fresh solder.
• For a lasting repair, pass a piece of wire-wrap wire through the empty via and solder it on both sides.

Systems

• Gottlieb System 80
• Gottlieb System 80A

Related tips

• Haunted House: no sound 16 in the sound test
• Haunted House switch matrix wiring
• Haunted House driver board: which transistor runs which coil
• Driving the Haunted House up-kicker from a pop bumper driver board
• Haunted House trap door won't open
• Score displays flicker
• Display fault: board or display?
• CPU chips to check for lamp faults

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