Using a PC power supply as an MPU bench supply: which wires

A PC power supply's 4-pin drive plug gives everything a Bally/Stern MPU needs to boot on the bench: red is +5 V, yellow is +12 V and both black wires are ground. Video game switching supplies work too. Crimp male pins into the plug and run them to alligator clips.

Systems

• Bally MPU AS-2518-17
• Bally MPU AS-2518-35
• Stern MPU-100
• Stern MPU-200

Related tips

• Where to clip a bench supply onto the MPU
• How the MPU sees the 43 V solenoid supply
• MPU LED never lights at all
• Power and ground pins of the main MPU chips
• Bench-testing a -133 MPU: swap the R113 diode for a resistor
• Double-check bench leads: a +12 V to +5 V short kills the MPU chips
• MPU stops before the 7th LED flash (no 43 V)
• MPU board test points

Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Two, Clay Harrell (pinrepair.com)