I've got a cheap no brand UNO clone that I used to control a simple CNC machine (bought it as a bundle with a CNC shield and stepper drivers). Now all of the sudden it just stopped working. Here's a picture of the board in question:
When I plug it in, the "on" and "L" leds light up, but nothing else. When I try to upload a sketch, there's no activity, not even the Rx or Tx leds flashing.
I've read you need separate drivers for these clones, because they use a different USB to TTL chip than the official Arduino boards, but I don't think that's the problem, since it worked fine before.
That is a CH340 based board.
You need to install the CH340/341 driver from here
What do mean it was working and under what OS ?
Two of my CNC use that board in win 7 x64.
Can you see the board when you plug it into your computer (without anything else attached) ?
If so upload BLINK to it but change the timing so you know it is your sketch that has gone to the board.
If that works then the board is fine and it may be one of your CNC components that is faulty.
It was working before in Windows 10. I could upload sketches and connect to my CNC software without any problems. Strange I need to install drivers all of the sudden, but I'll give it a shot.