Power supply bring-up, step 2: CPU load
Steps
- Connect power supply A2-P2 to CPU A1-J1 only; leave the other CPU and driver plugs off.
- Power on. Measure across C16 (top cap beside J1): 5.0 to 5.1 V.
- Measure C17 (just below it), black lead on its bottom lead: -11.9 to -12.1 V.
- If either sags, try the trimmer; anything under 4.8 V needs repair of the board or the plug.
Systems
Related tips
- Power supply bring-up, step 1: inputs
- System 1 power supply outputs
- Replacing power supply filter capacitor C1
- Getting to the power supply solder side
- Power supply output connector pins
- Quick checks on the similar System 1 power supply
- Display high-voltage section of the power supply
- Logic and display reference section of the power supply
Source: Gottlieb System 1 Pinball Repair from 1977 to 1980, Clay Harrell (pinrepair.com)