Sure enough, the genuine power supply worked like a charm, even on my brand new HD smart TV.tl

I purchased an authentic power supply, and now I am enjoying my favorite N64 games!The actual design itself is not terrible

A genuine power supply fixed the problem.

Eventually I concluded that the issue was in fact the power supply, and ordered a genuine N64 power supply instead

It worked, but it caused the system to have rolling scan lines that was fixed when a used authentic Nintendo power supply was substituted for this supply.