It is vital to be aware that ZTE has officially ended service and support for some hardware versions of the ZTE F600W (specifically version V7.1). (including the service hotline and remote support).
No. ZTE’s chipset is locked and binary blob-dependent. DD-WRT/OpenWrt is not available. Zte F600w Firmware Update
Do not reboot. Wait 10 minutes. If no progress, power cycle. Then try again via TFTP recovery. 99% failure is often a memory allocation error – reduce other processes on your PC. It is vital to be aware that ZTE