Upgrade the logic rectifier diodes CR1 and CR2
CR1 and CR2 (1N5401, 3 A 100 V) are marginal for the load; fit diodes rated at least 4 A.
Systems
Related tips
- Overvoltage protection on the logic supplies
- Spare diodes, capacitors and other parts for System 1
- Logic and display reference section of the power supply
- System 1 power supply shows about 110 V where 4 V and 8 V belong: wrong ground
- Quick checks on the similar System 1 power supply
- System 1 power supply outputs
- The 5/12 V supply is only half-wave rectified
- Getting to the power supply solder side
Source: Gottlieb System 1 Pinball Repair from 1977 to 1980, Clay Harrell (pinrepair.com)