3 Green Lights

I have a X-Carve CNC Router, that uses an Arduino Uno and a GShield card.

I have used this for a time with no issues. The other day I came back to the PC after being away from it for a few minutes. The program I use to upload G-code to the Arduino is UGCS. UGCS had a bunch of garbage characters on the screen.
I restarted the program, and have no function from the X-Carve anymore. I noticed the GShield lights for the 3 axis were remaining lit. Usually they light up when each axis operates.
I check out the Arduino as best I could. Everything functioned fine, except I can't reupload GRBL to the Arduino!
When I try to use everything as I had been, everything seems to work til I send code to run the machine.When I link to the Arduino with UGCS it acknowledges connection with the prompt "GRBL 9.0" as it should. I then send code, it appears as if it goes, but I receive no Acknowledgement back..as with the "OK" I usually get.

With everything off, I can push the axis and the appropriate light will lit on the GShield. As I said, I have used this before with no trouble, up til the garbage text on the UGCS screen.

Without knowing the code used to run on the Arduino, it is impossible to say what is wrong.

Your PC would be sending data for the Arduino to use to control the machine. If the program in the Arduino is corrupt, you will need to go back to the supplier.

Weedpharma