The correct firmware must match the exact model and region. For SCL-U31, common firmware variants include:
When your SCL-U31 turns into a digital brick, the most reliable solution is reinstalling the stock firmware using an SD Card (also known as the "dload" method). Unlike using complex PC tools (like SP Flash Tool or QPST), the SD Card method is safer, faster, and requires no drivers. Huawei Scl-u31 Firmware Sd Card
by powering off the device and holding Volume Up + Volume Down + Power simultaneously until the update screen appears. The correct firmware must match the exact model and region