Replace C33 on the speech and sound board

C33, a 0.1 uF capacitor next to pin 1 of the sound board edge connector, decouples the +30 V DC feed to the LM379S audio amplifier but is rated only 25 V, so it often burns. Change it for one rated well above 30 V before it fails.

Systems

• Gottlieb System 80

Games

• Black Hole
• Haunted House
• Mars God of War
• Volcano

Related tips

• Sound supply fuse F8 blows after the game runs a while
• Haunted House and Black Hole sound board DIP switches
• Sound aux supply keeps blowing its 2N6059: shorted capacitor on the 30 V rail
• Some or all sounds missing
• Special coil stays on even after replacing its driver chain (Rev 3)
• The System 80 sound board generations by game number
• No sound and a burning smell from the sound board: diodes, then the board
• Sound/speech board supplies on P1

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