This upgrade file applies for the ZR08ZN and ZR08ZM DVR.
You can find your DVR's model number on the label at the bottom of your DVR.
The below is the detail steps to upgrade the DVR:
(1). You needn't open the two upgrade files, please directly download the upgrade files
and save them to your U-disk.
(Please save the upgrade file rootfs-3520dv300 and u-boot-3520dv300 in the root
directory, not save it under any other folders.)
Note: it is better to use a 16GB or smaller flash drive with a Fat32 format.
(2). The files' name can not be have any changes, if the files' name change to
rootfs-3520dv300(1) and u-boot-3520dv300(1), the upgrade will be failed.
(3). Before starting to upgrade, please remove the mouse and unplug the power supply,
then plug the U-disk into the DVR's USB port, and plug the power supply.
(4). It can upgrade automatically as long as it has electricity, the upgrade process need
to last several minutes, please be patient.
(5). If the DVR stuck in ZOSI screen, please remove the U-disk, delete the rootfs-3520dv300 file,
and only save the u-boot-3520dv300 file in the root directory of the U-disk.
(6). Unplug the power supply, then plug the U-disk into the DVR's USB port, and plug the power
supply to upgrade again.
After upgraded, Please go to the DVR’s main menu – information – System to check the version.
If the upgrade was failed, we suggest you change another U-disk or USB port to try.
Please don't worry, if this can't help you, please feel free to contact us.