Sound/speech board supplies on P1

Connector P1 brings in regulated +30 V on pin 10, +12 V on pin 1, +5 V on pin 5 and -12 V on pin 3, with ground on pin 6; pin 7 is the audio output. Sound select lines S1, S2, S4 and S8 enter on P1 pins 8, 9, 11 and 12.

Systems

• Gottlieb System 80

Related tips

• Sound/speech board (A6) main chips
• Sometimes boots with a long tone and no sound: failed 6532 RIOT on the sound board
• Replace C33 on the speech and sound board
• Supplies on the original System 80 sound board
• Sound/speech power supply MA-149 parts
• Ground mod step 7: sound/speech power supply ground
• No sound at all
• Distorted sound

Source: System 80 Service Manual, Gottlieb