Firmware Zte Blade | L220

Hold the button (this is the boot key for most Unisoc devices).

: If the firmware is "bootlooping," you can enter recovery mode by holding Power + Volume Up (or Down) while the device is off. From here, you can perform a "Wipe Data/Factory Reset." Firmware ZTE Blade L220

If the device cannot read the SIM card or shows an invalid IMEI (International Mobile Equipment Identity), the radio firmware (baseband) is likely corrupted. Hold the button (this is the boot key