Lost Connection on PC and Mac

To start, I have followed every forum, video, tip and trick to no avail.

I have a xTool D1 Pro 20W. I have ran it for 2 months no issue. All of a sudden I started getting the Lost Connection Error seconds into a burn.

So I did some troubleshooting and did the following:

Put the laser on its own circuit to check if it is browning out or be disrupted by another device.
Issue still persisted.

I operated the xTool in the XCS software from xTool.
Had no issue. It completed multiple burns with no disconnection.

I connected the xTool to another pc and to my mac.
Issue still persisted.

I have fixed the USB setting in the power settings as I saw in one forum.

I have uninstalled Lightburn and reinstalled. I have wiped the profile setting folder. I have been dealing with this for a week. I have read everything and nothing gives a solution.

If anyone can help that would be excellent. I really don’t want to use XCS for my laser needs.

Hi Keith,

Please try changing the Transfer Mode in ‘Edit>Device Settings’ from buffered to synchronous.

You may have some luck using the potentially more stable V40.30.002.01B1 firmware

Tried both to no avail. It is still losing connection after 2 -10 secs and quitting the project.

I know this sounds dumb, but have you changed out the usb cord?


Yessir. Very first thing I did. Even bought a new high speed cable just to be sure.

I was suspicious but didn’t see a cable change on your list…

Good luck


1 Like

Thanks, I need it.

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