CNC controller LED screen is dark

The screen of the CNC controller suddenly turned dark during machining. Restart the power and the screen is still dark, adjust the screen brightness but it didn’t work, the letters can be seen by close look, and the other functions of the CNC lathe like X Z movements, tool changer, spindles are fine, so it should be the screen LED of the CNC controller screen burned.

Uninstall the CNC controller, there was burn smell, we saw the one of the DC-to-AC converter foot on the display circuit of the CPU board was burned, and the CPU board was covered with black dusts.

Uninstall the light of the LED screen, the light was fine, so changed the DC-to-AC converter, the LED screen resumed to work.

The reason is this CNC lathe was always working the casting, many dusts coming to the CNC controller which caused the DC-to-AC converter burned.

There is another possibility of the dark screen could be the LED light burned.