What If a Game Boy Had a CRT Display?

The original Game Boy may be a beloved console, but it shipped with a notoriously bad display. When it launched in 1989, LCD technology was still relatively new. To keep the cost and power consumption down, Nintendo selected an LCD that was mediocre by the standards of the time and downright abysmal by our standards today. It was kind of blurry, very susceptible to ghosting, and didn’t have any backlight at all. Modern dissatisfied gamers usually solve the problem with an LCD replacement made with current tech, but James went the other direction and gave his Game Boy a CRT display.

This is a more era-appropriate mod than a modern high-quality LCD screen, as the ‘80s and ‘90s were, of course, the heyday of CRT (cathode-ray tube) TVs and monitors. But historical accuracy is less important than the real motivation: fun. What could be more interesting than a Game Boy with a big honkin’ CRT? Thanks to the very nature of CRT mechanics, this solves the major problems with the Game Boy’s screen. Well, it would if everything worked properly.

James started by sourcing a small CRT, which he found on AliExpress. It was NOS (New Old Stock) and meant for use in video intercom systems. It runs on 12V and accepts a standard composite video signal. Unfortunately, the Game Boy couldn’t provide either of those—at least not as far as James could tell.

The power problem was relatively easy to solve with a boost converter, which James tapped in just after the power switch. Surprisingly, it could supply enough current to run the Game Boy and the CRT.

The video signal was a bigger challenge that James ultimately solved by buying one of those modern LCD replacements. That particular model offers “TV out” (audio and composite video) in addition to the LCD output. That could feed the CRT, so problem solved, right?

You guessed it: there was another hurdle. The LCD replacement’s controller board required that the user select the TV output from the onscreen menu, which would be hard for James to do if the LCD wasn’t actually present. After trying to modify the controller and failing, James settled on the brute force solution: using an ESP8266 board to automatically press the button sequence at startup. That ensures that it outputs video to the CRT without needing the LCD.

The final step was putting those components inside the Game Boy shell. James simply chopped that up and sandwiched the CRT in the middle. It isn’t the cleanest mod we’ve seen, but it certainly has gravitas.