Alphanumeric display board MA-644 parts

Each MA-644 board carries two 20-character glasses (DS1, DS2), driven by two 10939 digit drivers (XO-841) at U1 and U2 and a 10941 segment driver (XO-842) at U3. Zeners VR1 7.5 V (XO-844) and VR2 15 V (XO-843) and a 2N3906 (XO-588) at Q1 complete the supply side.

Systems

• Gottlieb System 80B

Related tips

• System 80B alphanumeric displays dark: check the display board supply
• What System 80B changed: three new boards
• System 80B display board connector A4J1
• Guarding the fill tip on the back of a score display
• System 80 schematics' 'offset' voltages are DC bias for the display filaments
• System 80B display driver chips 10939 and 10941
• System 80B displays stuck in reset

Source: Premier Technology Parts Catalog (System 80, 80A and 80B), Gottlieb / Premier