when i connect the monitor to Jetson NX, there is no signal but the same monitor works fine on Jetson Nano.When the NX is connected to the power supply, the fan will turn normally when it is hot.
Do you have ssh access? Or serial console? It isn’t unusual for video to have problems even when the system is otherwise fully functional. A serial console boot log would be quite useful. For NX dev kits the instructions should be the same as those for the Nano. See: