Search for <Sister Board> recovery image download instead of "Huawei S7721U". The binary may be identical, and the signature verification is tied to the chipset, not the logo.
For devices with an unlocked bootloader, you can manually re-flash only the recovery image using a PC.
In the BootLoad menu, choose "Enter filesystem submenu" to format the flash partition (ensure you have the image ready for upload). huawei s7721u recovery image verify failed link
: Navigate to the file system settings and clear the corrupted system software space to avoid block overlap conflicts.
The device should detect the file and begin the update/recovery process automatically. 3. Fastboot Recovery Flash (Advanced) In the BootLoad menu, choose "Enter filesystem submenu"
: Insert the card, power off the device, and hold Volume Up + Volume Down + Power simultaneously to enter forced update mode.
Many Huawei ONTs require for forced flash when web recovery fails. you'll need professional software tools.
If you can't access fastboot or eRecovery, your device might be in a "deep brick" state. For this, you'll need professional software tools.