Widely applied to PS2/3, Wii, Xbox, N64, PC, STB, VHS, VCR, DVD Players and other devices with standard composite AV output. You can get all your old gaming systems that output with RCA to 4K smart TV
If you get a blue screen, here is how to fix it (take the N64 as an example):
Unplug your N64.
Unplug the video converter from its power outlet.
Plug in the video converter power cable into an outlet again.
Make sure your switch is on 720p. You can try the other setting after it works.
Plug your N64 power cable into an outlet.
Insert HDMI and RCA cables.
Put in a game.
Turn on the N64.
(If still not, try replacing the RCA cable)