The line died.

That night, he updated his service list. New line item: "g935s u3 imei repair (z3x) – No questions asked. No phones returned. Cash only."

To an outsider, it was gibberish. To Leo, it was a cry for help.

He plugged the phone into his PC and launched Z3X. The software detected the Samsung Exynos chipset. He clicked the "Repair IMEI" tab, but an error flashed: "Security Binary U3 – Write Protected."

Leo turns off the lights. Some ghosts don't need a signal. They just need a repair.

He performed a "certificate swap." He used Z3X to extract the g935s’s genuine IMEI certificate, then patched the S20+’s bootloader to accept it as a "ghost certificate." The software reported: "Patching U3防回滚... Success. Writing cert... Done."

Then the phone rang.