How to turn a broken Samsung phone into a Mini PC - without a BATTERY!!

Summary

The video demonstrates converting a damaged Samsung Galaxy S20 into a compact Samsung DeX mini PC by removing its battery and installing the phone’s motherboard in a small case.

Build guide and key components

• The host carefully opens the phone, disconnects and removes the battery, then salvages its management board. The board is wired to a voltage regulator to provide battery-like power to the phone.
• The power setup takes 5 V input and provides a steady output of about 4.1 V. A 470 µF capacitor helps smooth voltage fluctuations.
• Testing showed that 5 V at 3 A worked reliably. A 1 A supply was insufficient, while a 2 A supply struggled. Several other regulator boards caused boot loops, which the host attributes to unstable output voltage during startup.
• The phone’s motherboard is fitted into a compact enclosure alongside a USB-C hub, HDMI access, a heatsink, and a fan. The fan is modified to run from USB using its positive and negative wires.
• A physical power button is retained because supplying power alone does not turn on the phone or start DeX. The build also includes USB connectivity for a wireless keyboard and mouse.
• The host emphasizes checking cable and board orientation during assembly, insulating exposed connections, and allowing room for cooling.

Removing the battery requires particular care: puncturing a lithium-ion battery can be dangerous.

Results and observations

• The finished device boots into Samsung DeX and connects to a TV or display through HDMI.
• Demonstrated uses include Jellyfin and Amazon Prime Video, Android gaming, and emulators. The host reports smooth performance in the tested games, with no dropouts or overheating during several weeks of use.
• Although the phone has no battery, its battery indicator starts at 92% and declines very slowly. After 12–14 hours of daily use, the lowest reported reading was 64%. The host does not establish what happens when the indicator reaches zero.
• The host presents the project as a way to repurpose a battered phone into a more PC-like media or gaming device, while noting that simply connecting a phone to a TV is a simpler option.

Main speaker and source

A single unnamed host from Fixing Modding Building narrates the repair, electronics testing, assembly, and final demonstrations.