+1 Measure the voltages on the connector. There's a pinout diagram further down on this page: https://retrogamestart.com/answers/replace-c64-power-supply-volt

+1 Measure the voltages on the connector. There's a pinout diagram further down on this page: https://retrogamestart.com/answers/replace-c64-power-supply-voltage-failure-will-kill-your-c64 https://retrogamestart.com/answers/replace-c64-power-supply-... I've seen a bad power supply kill one of the two CIAs, the color ram & damage the SID on a C64C