@liping The trial is limited to 10,000 lines of raster and 1,000 lines of vector G-code, you can check the simulation "view" to see what was generated and will be sent to your machine.

@fuentalba It could be the diode has failed or perhaps your parameters have changed.

@Antonio-D'Elia Use T2Laser and my firmware, all problems will be solved and you will get much better performance from your machine.

@Владимир-Айнов What software? I highly doubt that is T2Laser (as you are getting darker start and finish plus these gaps, all problems solved in my software), but if so you can check the simulation "view" to see if that's a G-code issue or a machine problem.

@kdaffy Resolved by email.

@kdaffy Enter your license key, and it should register again. If not send me an email and I will help you.

@feldwebel2012 Agreed, and I just replied to your other post. I did see a 3 pack on Amazon for ~$12 but didn't check to see if they had the bootloader or not, the link I provided was just the top of the search list (with prime delivery selected) but I did confirm it was a genuine Atmel chipset and included the bootloader.

@feldwebel2012 Any Nano, a genuine Arduino or a clone will work. I recommend buying one with a genuine Atmel ATmega328p microprocessor and you would also want it to have the bootloader already installed.

I have used these brands: HiLetGo, Geekcreit and Sainsmart but others should work just as well. They are ~$3 from places like Banggood but you can get them faster from Amazon or a local ebay seller for around $6.

This was just the first one to come up on Amazon with Prime selected (example) https://www.amazon.com/Arduino-Board-ATmega328P-Micro-Controller-Projects/dp/B07X5VQ9XH/ref=sr_1_6?keywords=arduino+nano&qid=1575719510&sr=8-6

@OndraKulhavy Your Grbl parameters (firmware) have changed, there should be a calibration option to fix it or you could reset the firmware. Sorry I have no idea where to find these in elekscam as I've never used it.