# Lost MCU connection

**URL:** <https://klipper.discourse.group/t/lost-mcu-connection/7341>\
**Category:** General Discussion\
**Created:** [March 19, 2023, 7:34am UTC](https://klipper.discourse.group/t/lost-mcu-connection/7341 "2023-03-19T07:34:21Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Decapper](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/decapper/32/2135_2.png) [@Decapper](https://klipper.discourse.group/u/Decapper)\
**Post date:** [March 19, 2023, 7:34am UTC](https://klipper.discourse.group/t/lost-mcu-connection/7341/1 "2023-03-19T07:34:21Z")

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### Basic Information:

Printer Model: Chiron  
 MCU / Printerboard:SKR3  
 `klippy.log`

[klippy.zip](https://klipper.discourse.group/uploads/short-url/1mXaDHLnS91RTUHPKNacZO6aCoB.zip) (2.2 MB)

Hi, I’ve had a problem for sometrime now with my printer that is very frustrating. Prints will stop after sometime anywhere from 2hrs to 5hrs with an MCU communication error.

Things I’ve tried.  
Replace USB cable  
Isolate positive and negative of USB

Anyone got any other ideas?

I’ve tried all of these [Timeout with MCU / Lost communication with MCU](https://klipper.discourse.group/t/timeout-with-mcu-lost-communication-with-mcu/6639)

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**Author:** ![hcet14](https://avatars.discourse-cdn.com/v4/letter/h/ecd19e/32.png) [@hcet14](https://klipper.discourse.group/u/hcet14)\
**Post date:** [March 19, 2023, 12:49pm UTC](https://klipper.discourse.group/t/lost-mcu-connection/7341/2 "2023-03-19T12:49:50Z")

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> [@Decapper](#):
>
> Isolate positive and negative of USB

Just pull jumper “VUSB”

Have you tried other USB connectors on your SBC?

You may have a look here [Tronxy x5sa-2e V10 F446 board not staying connected - #7 by hcet14](https://klipper.discourse.group/t/tronxy-x5sa-2e-v10-f446-board-not-staying-connected/7236/7) and ask @KazWahs if it solved his issues.

Good luck, hcet14

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**Author:** ![Decapper](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/decapper/32/2135_2.png) [@Decapper](https://klipper.discourse.group/u/Decapper)\
**Post date:** [March 25, 2023, 9:08am UTC](https://klipper.discourse.group/t/lost-mcu-connection/7341/3 "2023-03-25T09:08:14Z")

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I disabled my auto shutdown and left the printer running idle. And noticed after sometime I got this message. Does this just mean that it lost connection with my printer board “MCU”

> Can not update MCU ‘mcu’ config as it is shutdown  
> Once the underlying issue is corrected, use the  
> “FIRMWARE\_RESTART” command to reset the firmware, reload the  
> config, and restart the host software.  
> Error configuring printer

And in the the log is the below repeated over and over again.

> Args: [‘/home/pi/klipper/klippy/klippy.py’, ‘/home/pi/klipper\_config/printer.cfg’, ‘-l’, ‘/home/pi/klipper\_logs/klippy.log’, ‘-a’, ‘/tmp/klippy\_uds’]  
> Git version: ‘v0.11.0-148-g52f4e20c’  
> CPU: 4 core ARMv7 Processor rev 3 (v7l)  
> Python: ‘3.7.3 (default, Jan 22 2021, 20:04:44) \n[GCC 8.3.0]’  
> webhooks client 3044842544: {‘program’: ‘Moonraker’, ‘version’: ‘v0.8.0-29-g80920dd’}  
> =============== Log rollover at Sat Mar 25 00:00:00 2023 ===============  
> mcu ‘mcu’: got {‘oid’: 16, ‘next\_clock’: 132878336, ‘value’: 31382, ‘#name’: ‘analog\_in\_state’, ‘#sent\_time’: 21434.888771075, ‘#receive\_time’: 21435.433375186}  
> mcu ‘mcu’: got {‘oid’: 18, ‘next\_clock’: 140878336, ‘value’: 6249, ‘#name’: ‘analog\_in\_state’, ‘#sent\_time’: 21434.888771075, ‘#receive\_time’: 21435.453361242}  
> mcu ‘mcu’: got {‘oid’: 16, ‘next\_clock’: 252878336, ‘value’: 31382, ‘#name’: ‘analog\_in\_state’, ‘#sent\_time’: 21434.888771075, ‘#receive\_time’: 21435.733383519}  
> mcu ‘mcu’: got {‘oid’: 18, ‘next\_clock’: 260878336, ‘value’: 6250, ‘#name’: ‘analog\_in\_state’, ‘#sent\_time’: 21434.888771075, ‘#receive\_time’: 21435.753352056}  
> mcu ‘mcu’: got {‘oid’: 16, ‘next\_clock’: 372878336, ‘value’: 31380, ‘#name’: ‘analog\_in\_state’, ‘#sent\_time’: 21435.873163538, ‘#receive\_time’: 21436.033385945}  
> mcu ‘mcu’: got {‘oid’: 18, ‘next\_clock’: 380878336, ‘value’: 6250, ‘#name’: ‘analog\_in\_state’, ‘#sent\_time’: 21435.873163538, ‘#receive\_time’: 21436.053398797}  
> mcu ‘mcu’: got {‘oid’: 16, ‘next\_clock’: 492878336, ‘value’: 31381, ‘#name’: ‘analog\_in\_state’, ‘#sent\_time’: 21435.873163538, ‘#receive\_time’: 21436.333396371}  
> mcu ‘mcu’: got {‘oid’: 18, ‘next\_clock’: 500878336, ‘value’: 6248, ‘#name’: ‘analog\_in\_state’, ‘#sent\_time’: 21435.873163538, ‘#receive\_time’: 21436.35341276}

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**Author:** ![EddyMI3D](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/eddymi3d/32/1981_2.png) [@EddyMI3D](https://klipper.discourse.group/u/EddyMI3D)\
**Post date:** [April 28, 2024, 10:47am UTC](https://klipper.discourse.group/t/lost-mcu-connection/7341/4 "2024-04-28T10:47:13Z")

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