Press and hold simultaneously. The device should detect the file and begin the update automatically. 2. Try Huawei eRecovery
This failure usually occurs when the system detects that the recovery or boot image has been altered or corrupted. Common triggers include: huawei s7721u recovery image verify failed link
Power cycle the switch. When you see Press Ctrl+B to enter BootROM menu... , press Ctrl+B immediately. Default password: Admin@huawei (or huawei123 for older units). Press and hold simultaneously