RetroSonicHero

Yep a bad PSU can cause all sorts of weird and wonderful artifacts. They're getting to the age now where failure is becoming more common. Many people tend to overlook PSU's when doing cap replacements to their board.

I have a box full of mk-1602 and mk-2103 psu's that I'm increasingly more hesitant to use.  I feel better using modern replacements from retrogamecave.

@bluejay Yeah, like Twenty said, they're at the point where failure is common. Thankfully though, unlike some other consoles, they're VERY unlikely to spontaneously combust. Generally they'll just display graphical artifacts such as wavy lines moving down the screen, and then eventually they'll just stop working.

I think the best course of action is to just be using modern replacements from here on out. As long as it matches the specs the console needs and is well made, you're better off using that.