In a nutshell: A Steam Deck mod built inside a Game Boy-sized case is nearing a key milestone: adding its internal display. The project, called SteamBoy, already has a working Steam Deck motherboard, battery, speakers and controls inside a custom case modeled after Nintendo's original handheld. However, the SteamBoy is still a work in progress, with the display remaining the largest unfinished component.
Fitting the AMOLED panel, completing the adapter board and applying the BIOS modification will determine whether the device can function as a self-contained handheld.
As the next step, creator PhyFawkes plans to install a 1,200 x 1,080 AMOLED panel with a 90 Hz refresh rate. The panel was originally designed for VR use, so it cannot connect directly to the Steam Deck's hardware. A custom adapter PCB is being designed to connect the Deck's display ribbon cable to the new screen.
The mod will also require a BIOS modification. PhyFawkes said the firmware work will be similar to modifications used in the DeckHD and Deck Sight projects. Until the display is installed and working, the SteamBoy can only be used with an external monitor.
"Hopefully it won't be too long before that's working as well," PhyFawkes wrote in a comment on a video showing the device running.
The build started with a simple question about the Steam Deck's internals. "The Steam Deck motherboard seems pretty small," PhyFawkes wrote. "I wonder if you could make a Steam Deck the size of a Game Boy?"
The project shows that much of the hardware can fit inside a much smaller enclosure. "It has a fully functional LCD Steam Deck motherboard, battery, speakers, and all the face buttons you see here. No custom PCBs needed (so far), and all within the dimensions of a Game Boy," PhyFawkes said.
That is the main technical point of the build. The modder has not needed to replace the Deck's main hardware or create custom control boards to make the system work in the smaller case. The display is the first component that requires a purpose-built circuit board.
SteamBoy Teardown and Assembly
by u/PhyFawkes in SteamDeckModded
Cooling is another challenge in the tightly packed enclosure. PhyFawkes used a 30 x 7 mm fan and heatsink from AliExpress, mounted with a custom 3D-printed bracket. The system also uses a slight undervolt to reduce heat. During gaming, temperatures have reportedly ranged from 70 to 80 degrees Celsius.
Teardown photos posted on Reddit show the Steam Deck components arranged inside the Game Boy-style shell. The design retains the general shape and control layout of the original handheld, but the system inside is built around Valve's modern portable PC hardware.
For now, the project demonstrates that a functional Steam Deck can be reduced to a much smaller, retro-style form factor without modifying its core motherboard, battery, speakers or controls.
