What to do when monitor does not display video?

My NVR stopped displaying the image on a 4K TV. During the NVR restart, it appears on the TV as “Techage” in 800×600 resolution. Later, there is no image on the TV. The NVR and cameras work over the network. Changing the resolution in the NVR does nothing, no image, even on TV. The function is also on the monitor, also no image. Please help.

На мониторе при включении загорается заставка Techage . Дальше просто чëрный экран. Не открывает ничего.

I just received this camera as a replacement. When I plug it in, I get the message “Unsupported stream type.” How can I use this with my system? How do I identify the proper camera to order?

I have the same issue as above. I have also tried with 2 monitors using bothe VGA & HDMI connections. Please let me know what I can do.

I previously bought a set of two cameras with a PoE receiver from you. The receiver (N6704F45N-POE) stopped starting, the hard drive turns on, starts working, there is no boot screen on the screen, does not show an image on the monitor, does not connect to the Internet via cable, two green diodes and one red light up inside the receiver on the boards. All wires have been checked and connected, I have already turned off the power and turned it on, but nothing is displayed on the screen, even the DVR loading screen does not start, and the connection through the mobile application also does not occur. Cable and internet have been checked. The DVR itself does not work. What to do? I need your help. What do you need to restart the DVR?