Meter check of the display board 7432

Steps

• The 7432 OR gate makes the comma on seven-digit displays and the "1" on four-digit displays.
• Black lead on pin 7 (ground): high resistance to every pin except the tube outputs, pins 3 and 6.
• Red lead on pin 7: about 25K to 30K ohms to all pins.

Systems

• Gottlieb System 80
• Gottlieb System 80A

Related tips

• Meter checks on a display tube
• The display voltages to check
• How the Gottlieb fluorescent displays work
• Measuring voltages on a display board
• Checking the +60 V filter caps on a display board
• Replacing a display glass tube
• How the System 80 fluorescent displays light
• Use the shared wiring to locate display faults

Source: Troubleshooting Gottlieb Displays (On Target technical newsletter, vol. 3 issue 7, 1982), Gottlieb "On Target"