Lost communication with MCU 'nhk' Nitehawk keeps disconnecting

[KastenTaco]

My Nitehawk keeps disconnecting about an hour into each print.
At this point I have checked all connectors multiple times, made sure things don't overheat (47C max temperature), re-flashed Klipper, replaced the RPI, and tried a new USB cable.
All to no avail. It seems somewhat random, and I am at a loss.

Are there any known hardware or quality issues with the board itself? This is the only component I can not test and verify.

[R-yang1]

Hi, this is Rebecca from LDO team.
Could you please send a email to support@ldomotors.com with a picture of wiring and the klippy.log?

Thanks.

[patlap13]

I had the same issue. a soon as toouch yhe cable I got the error

[Daisy1819]

I had the same issue. a soon as toouch yhe cable I got the error

Hi, Could u write an email to describe your problem to our support account, it should be support@ldomotors.com.

[patlap13]

I found the problem actually The connector is getting looser and Connor stay un place I’m designing a retainer fie the Galileo extruder.

…

Sent from my iPad On Dec 25, 2024, at 20:43, Daisy1819 ***@***.***> wrote:  I had the same issue. a soon as toouch yhe cable I got the error Hi, Could u write an email to describe your problem to our support account, it should be ***@***.******@***.***>. — Reply to this email directly, view it on GitHub<#10 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ABIAT7GWZNNJTP6RPXSZOA32HNNK5AVCNFSM6AAAAABM6I747CVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKNRSGA3DINZTGU>. You are receiving this because you commented.Message ID: ***@***.***>

[Daisy1819]

Glad to hear that. If the connector is loose, i recommend u can use a tweezers to enlarge the connect ports, it may help. Best regards, Daisy ***@***.*** From: NurseKate Date: 2024-12-26 18:01 To: MotorDynamicsLab/Nitehawk-SB CC: Daisy1819; Comment Subject: Re: [MotorDynamicsLab/Nitehawk-SB] Lost communication with MCU 'nhk' Nitehawk keeps disconnecting (Issue #10) I found the problem actually The connector is getting looser and Connor stay un place I’m designing a retainer fie the Galileo extruder.

…

Sent from my iPad On Dec 25, 2024, at 20:43, Daisy1819 ***@***.***> wrote:  I had the same issue. a soon as toouch yhe cable I got the error Hi, Could u write an email to describe your problem to our support account, it should be ***@***.******@***.***>. — Reply to this email directly, view it on GitHub<#10 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ABIAT7GWZNNJTP6RPXSZOA32HNNK5AVCNFSM6AAAAABM6I747CVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKNRSGA3DINZTGU>. You are receiving this because you commented.Message ID: ***@***.***> — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.Message ID: ***@***.***>

[Daisy1819]

like the photo. ***@***.*** From: daisy Date: 2024-12-27 14:36 To: MotorDynamicsLab/Nitehawk-SB; MotorDynamicsLab/Nitehawk-SB CC: Comment Subject: Re: Re: [MotorDynamicsLab/Nitehawk-SB] Lost communication with MCU 'nhk' Nitehawk keeps disconnecting (Issue #10) Glad to hear that. If the connector is loose, i recommend u can use a tweezers to enlarge the connect ports, it may help. Best regards, Daisy ***@***.*** From: NurseKate Date: 2024-12-26 18:01 To: MotorDynamicsLab/Nitehawk-SB CC: Daisy1819; Comment Subject: Re: [MotorDynamicsLab/Nitehawk-SB] Lost communication with MCU 'nhk' Nitehawk keeps disconnecting (Issue #10) I found the problem actually The connector is getting looser and Connor stay un place I’m designing a retainer fie the Galileo extruder.

…

Sent from my iPad On Dec 25, 2024, at 20:43, Daisy1819 ***@***.***> wrote:  I had the same issue. a soon as toouch yhe cable I got the error Hi, Could u write an email to describe your problem to our support account, it should be ***@***.******@***.***>. — Reply to this email directly, view it on GitHub<#10 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ABIAT7GWZNNJTP6RPXSZOA32HNNK5AVCNFSM6AAAAABM6I747CVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKNRSGA3DINZTGU>. You are receiving this because you commented.Message ID: ***@***.***> — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.Message ID: ***@***.***>

[JJayzX]

I've been getting this issue intermittently with new board but is now suddenly constant. It is not the connection as it has happened while in heating phase, so no movement, and no matter what I move around does not cause it to disconnect. Mainboard is Manta M8P v2 with RPi 5 and all the software is updated to today.

[z00mantwo]

I had a similar problem. Switching the Nitehawk to the USB 2.0 port on my Raspberry Pi 4b with the other USB 2.0 port empty has fixed it for me.

[Daisy1819]

Did u mean change the blue port to the black port on the usb port? ***@***.*** From: z00mantwo Date: 2025-08-16 06:17 To: MotorDynamicsLab/Nitehawk-SB CC: Daisy1819; Comment Subject: Re: [MotorDynamicsLab/Nitehawk-SB] Lost communication with MCU 'nhk' Nitehawk keeps disconnecting (Issue #10) z00mantwo left a comment (MotorDynamicsLab/Nitehawk-SB#10) I had a similar problem. Switching the Nitehawk to the USB 2.0 port on my Raspberry Pi 4b with the other USB 2.0 port empty has fixed it for me. — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.Message ID: ***@***.***>

[Daisy1819]

U can try to change the Nitehawk USB 3.0 to USB 2.0 on Pi. ***@***.*** From: JJayzX Date: 2025-08-16 04:06 To: MotorDynamicsLab/Nitehawk-SB CC: Daisy1819; Comment Subject: Re: [MotorDynamicsLab/Nitehawk-SB] Lost communication with MCU 'nhk' Nitehawk keeps disconnecting (Issue #10) JJayzX left a comment (MotorDynamicsLab/Nitehawk-SB#10) I've been getting this issue intermittently with new board but is now suddenly constant. It is not the connection as it has happened while in heating phase, so no movement, and no matter what I move around does not cause it to disconnect. Mainboard is Manta M8P v2 with RPi 5 and all the software is updated to today. ― Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.Message ID: ***@***.***>

[z00mantwo]

Blue is USB 3.0. White is USB 2.0. I think having it by itself on one side or the other is the important thing.

[Daisy1819]

Thanks for explanation. ***@***.*** From: z00mantwo Date: 2025-08-19 05:57 To: MotorDynamicsLab/Nitehawk-SB CC: Daisy1819; Comment Subject: Re: [MotorDynamicsLab/Nitehawk-SB] Lost communication with MCU 'nhk' Nitehawk keeps disconnecting (Issue #10) z00mantwo left a comment (MotorDynamicsLab/Nitehawk-SB#10) Blue is USB 3.0. White is USB 2.0. I think having it by itself on one side or the other is the important thing. — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.Message ID: ***@***.***>

[OldManAnders]

I have a similar experience, mine started about 2 weeks ago, prior to that I could easily print 6-10 hour prints, but now I get the "Lost communication with MCU 'nhk'" error 1-2 hours into a print.
I have checked all the cables, and even replaced the USB-cables with isolated cables. The temperature of the Nitehawk never exceeds 55 degrees, and I have put EM-protective tape on the connector to protect from the extruder stepper.

When I run dmesg on the Rpi-4 I get this:
[12348.695246] usb 1-1.4: USB disconnect, device number 5
[12349.428835] usb 1-1.4: new full-speed USB device number 7 using xhci_hcd
[12349.537741] usb 1-1.4: New USB device found, idVendor=1d50, idProduct=614e, bcdDevice= 1.00
[12349.537761] usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[12349.537767] usb 1-1.4: Product: rp2040
[12349.537772] usb 1-1.4: Manufacturer: Klipper
[12349.537777] usb 1-1.4: SerialNumber: 4E363334320B2890
[12349.543164] cdc_acm 1-1.4:1.0: ttyACM0: USB ACM device`

Klippy.log just says that it loses connection so it must be something with the USB-Serial connection that gets broken.

Host: RPI 4B rev 1.5
Mainboard: BTT Octopus 1.1
Toolhead: Nitehawk-SB (rpi 2040)

What I have tried:

• Completely rewired and recrimped the all connections
• Exchanged all USBs (Mainboard-RPI, Nitehawk-RPI)
• swapped to external powersupply for RPI
• tried USB3 and USB2 connections (both MCUs in the same and one in each)

I'm starting to think that the board is just dying, which is honestly very sad considering it has had 'only' 150hours print time on it.

[KastenTaco]

I have found a possible solution. It seems that there is electrostatic charge building up in the PTFE tube that sporadically discharges into the USB chip on the Raspberry Pi, which instantly kills the connection.

First, make sure the PTFE tube feeding the tool is correct. It should have 3mm ID and 4mm OD. This reduces friction, which in term reduces the potential for static building up.

Next, try to ground the extruder stepper to one of the endstop pins on the Nitehawk. Just putting a cable shoe under one of the mounting screws should be enough in most cases.

If all fails, you might want to consider switching extruders. I was running a CW2 and was still seeing the issue sporadically. However, I have since switched to a Galileo-based extruder and have no longer had any issues.

Please try all of the above and report back if any of those have helped!!!

[z00mantwo]

Try adding

usbcore.autosuspend=-1

to the end of the line in your /boot/cmdline.txt or /boot/firmware/cmdline.txt depending on the version of the OS you have.

Has to be at the end of the single line that is in the cmdline.txt. With a space before it. This will prevent the OS from trying to save power by turning off USB devices. It has helped clear up issues with long prints for me. Hopefully this will help.