A Samsung Galaxy A90 5G smartphone, originally bought for about 30 dollars (around 26 euros) due to a cracked OLED screen, has been transformed into a mini PC by a YouTuber named ETA Prime. The phone, launched in September 2019, includes a Snapdragon 855 processor, 6 GB of RAM, and 128 GB of storage. To convert it into a mini PC, the YouTuber removed the screen, cameras, and outer casing, keeping the motherboard, a small power supply card, and the battery. The components were placed into a 3D-printed case that holds 0.7 liters, with added parts like a USB-C hub that supports HDMI output, a recycled smartphone heatsink used as a cooling system, and a power button connected directly to the motherboard. The overall cost of the project was about 50 dollars (approximately 43 euros). This project is part of a series of similar experiments. In February 2026, ETA Prime used the motherboard from a Galaxy S20 FE with a broken screen and placed it inside a Raspberry Pi case. That project cost less than 100 dollars (around 85 euros) and used a Snapdragon 865 processor to run games like Hollow Knight: Silksong at 60 frames per second using an emulator called GameNative, as well as PS2 games at full speed. Samsung introduced a feature called DeX desktop mode for high-end Galaxy smartphones in 2017. This mode allows users to display resizable windows, a taskbar, and true multitasking, similar to a traditional PC. The YouTuber tested the Galaxy A90 5G under DeX and found it could run a full browser with Chrome extensions, ad blockers, and password managers. It also ran Minecraft at over 200 frames per second during gameplay and more than 400 frames per second in open areas, with temperatures reaching 42 degrees Celsius after use. While the mini PC made from the Galaxy A90 5G is limited to Android applications and cannot run Windows or x86-based programs, it offers a much lower price and smaller size compared to an entry-level mini PC with an Intel N100 processor, which typically costs around 150 euros. The device still includes a 4,500 mAh battery, providing independent operation that is rare in mini PCs. However, some viewers have expressed concerns about the safety of housing a lithium battery in a small, enclosed space and the lack of proper ventilation in the case. Samsung has included DeX in its One UI 8 software, which began rolling out in September 2025. Google has also added a native desktop mode to Android 16, based on DeX technology. Although Samsung has expanded DeX support to some of its flagship devices, including the Galaxy Z Fold 2, Z Flip 7, and Tab S tablets, the Galaxy A90 5G remains the only A series phone with access to DeX. The latest version of DeX in One UI 8 has lost some features from the older "classic" version, such as connected screen settings and certain right-click options. However, third-party apps can restore some of these functions. The DeX for PC application, though, was removed with the release of One UI 7.