NVR won't boot up after PAK update - RLK4-210B4

I've been working with your team via e-mail. Today I downloaded the 'pak' file. I followed your instructions; format to FAT32, copy the PAK file to USB, plug it in and so on. After a couple of minutes, the NVR rebooted and now nothing. The display won't come up. The lights are on in front, however, no blinking. How can this be fixed?

To add more details. I followed your instructions. I put the USB into the NVR. I then went to the maintenance screen and selected update from USB. I selected the PAK file, which there was only one file on the USB. After a few moments, it appear to reboot but nothing. The screen is black. The power LED and HDD LED are on but solid and not displaying.

Hi Onekolcj1,

Sorry for the problem, it seems the upgrading failed and damaged the flash. We have arranged a new replacement to you. Hope you will continue to enjoy the system. Thanks.