USB dropping connection

Machine: laser engraving cutting machine model hq3020

Board: Cohesion3D LaserBoard

Firmware: _Smoothie

Problem/ Question:I have been running lots of projects no worries. In the last 24 hours I keep losing connection. The project will start, disconnect anywhere between 2-10 seconds in. I have tried the following.

New USB cable with shielding.
Disabled USB sleeping in power management settings (later on 2nd PC as well.)
Changed USB Ports
Recreated the file I was making to ensure it was not that.
Uninstalled and Reinstalled Lightburn.
Changed from one Desktop to another desktop computer.
Minimized USB connections in the same port.

I’m not really sure what else I should do. I think it must be something to do with the board as it has followed across two separate computers.

On a strange side note my automatic bedsize was not detected on the 2nd machine :confused:
Did you provide those pictures? We need pictures to understand your setup!![] -

What software are you using? (And what is the version of that software?)

Lightburn-v0.9.20.exe (64 Bit)

If you reinstall ver 0.9.19 do you still have the same connectivity issues?

Just uninstalling v.20 and trying .19 now. I shall let you know.

No. Made no difference :frowning:

Hi James,

Welcome to the forum! I have upgraded your trust level so that you can now upload photos.

Your LPSU is very close to the LaserBoard inside of the electronics compartment. The stock power supplies can cause interference. Interestingly, this is the furthest to the front I have seen one located inside the chassis before. Try moving it further back and bolt it to the chassis for grounding.

1 Like

I have moved it back as far as it would stretch. It seemed to work as I got around 7 seconds, then it kept stopping after only a few seconds. Here is my Lightburn console:

BlockquoteWaiting for connection…
Smoothie
ok
ok
Homing
ok
Project loaded in 20 milliseconds
Starting stream
Layer C01
Connection lost
Stream completed in 0:02
Smoothie
ok
ok
Homing
ok
Starting stream
Layer C02
Connection lost
Stream completed in 0:03
Smoothie
ok
ok
Homing
ok
Starting stream
Layer C02
Connection lost
Stream completed in 0:03
Smoothie
ok
ok
Homing
ok

Blockquote

Hi James,

Are you using the original USB cable that came with your machine? We recommend using a high quality, shielded cable that is no longer than 16 feet.

Check out this document for common solutions to dropout issues: USB Dropouts and Brownouts

Hi, no I’m not. I purchased a gold plated shielded USB cable as part if my troubleshooting.

Great, let me know what steps you walk through on the doc and we will go from there. Sorry, I missed that in your original post.

Specifically, have you done any Windows updates recently?
Try isolating your machine and computer on a different circuit from any other appliances and the control board.
Try using a powered USB Hub.
Check your machine grounding - I can give instructions on how to test, if needed.

May I have the test instructions please. I’ll purchase a powered usb connection now.

Unplug your K40 from the wall to test continuity. Set your multimeter to measure Resistance, then place probes on the earth pin of your power lead wire and any exposed (unpainted) metal on the case of your K40 (other than the ground bolt on the machine). Your multimeter should indicate very low resistance (i.e., under 10 ohms).

Check all of your wiring, screw terminals, pins, etc. to make sure everything is making contact properly.

1 Like

My powered USB connection has arrived and been tested. No luck. Will do the grounding test after Xmas.

Hi James,

Just following up to see if you had a chance to do the grounding test yet. Hope you had lovely holidays!

I’m just trying to do a service to those who have bought this board… get a big ferrite clip… wind your usb around it 2x . After that most likely you’ll be good. Look me up. See all my posts. Sometimes I’m an asshole, but it took me a while to get this 200$ board to work