In a short and satisfying build video, Chicken 64 introduces his homemade Commodore 64 PSU tester, a simple tool designed to check C64 power supply units both at idle and under load. For anyone tired of guessing whether a power brick is healthy or secretly frying chips, this tool offers a surprisingly elegant fix.
Using analog gauges and a 1-amp load per rail, the Commodore 64 PSU tester provides immediate voltage readings on both the 5V DC and 9V AC lines. It not only shows whether a PSU looks fine at idle, but more importantly, whether it holds up under stress. And spoiler alert: not all of them do.
Testing Real-World C64 PSUs
Chicken 64 runs five power supplies through the tester—two are clearly faulty, two pass with decent scores, and one… well, let’s say it tried. One unit’s voltage literally degrades on camera from 3V to under 1V when a load is applied—cue the sad trombone.
And just because a power supply seems fine on a multimeter doesn’t mean it won’t cause slow and silent damage. One PSU measures okay unloaded, but under pressure it drops below 4.2V, risking your chips every time you boot up.
Build Details and Design Simplicity
The tester itself is about as DIY as it gets: a handful of analog meters, resistors to apply the load, and toggle switches for control. Chicken 64 used parts he had on hand—some of which burned out dramatically during development (RIP gauge #1). Despite the mismatched hardware, the unit works flawlessly.
There’s no fancy PCB here—just a functional wiring diagram, a basic enclosure, and a clear purpose: eliminate PSU guesswork.
