Hey, i have hikvision DVR model no. DS-7216HGHI-F2. I have updated the firmware with batch configuration tool and it shows update successful. after it Dvr is rebooting continues it just show logo and reboot. i use to update with hikvision tftp but is showes "TFTP server [192.0.0.128] initialized". when i try to update with serial cable uboot ctrl+U is not working. please how to fix it.