Need some help here. My Hikvision DS-7608N-E2 8P has gone into 15 beeps and then reboot itself after firmware upgrade. I can ping both 126.96.36.199 and 188.8.131.52 but I'm not able to see NVR taking the file. Is there a special cable to connect to the board, like a usb to pin? If so, you what type of cable is that? Thanks.