I have a ACMER S1 and was going along fine with that. Decided to get the Longer RAY5. The Lightburn would not connect with LongerRAY5 and now the Acmer doesn't work

LightBurn Hardware Compatibility GRBL
1

lasors won’t connect

2

In your windows device manager, is your computer recognizing the machine is connected and assigning the laser a COM port?

You may need to install drivers: Drivers - LightBurn User Guide

3

For the Longer Ray 5 try enabling the DTR Signal toggle.