# Suddenly mcu unable to connect Vzbot/bttcb1

**URL:** <https://klipper.discourse.group/t/suddenly-mcu-unable-to-connect-vzbot-bttcb1/23453>\
**Category:** General Discussion\
**Created:** [May 14, 2025, 8:23pm UTC](https://klipper.discourse.group/t/suddenly-mcu-unable-to-connect-vzbot-bttcb1/23453 "2025-05-14T20:23:55Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\
**Post date:** [May 15, 2025, 6:08am UTC](https://klipper.discourse.group/t/suddenly-mcu-unable-to-connect-vzbot-bttcb1/23453/2 "2025-05-15T06:08:20Z")

</div>

```auto
[Errno 2] No such file or directory: '/dev/serial/by-id/usb-Klipper_stm32f407xx_3C004F001850314335393520-if00'

```

This means no printer board with the respective serial path is found to be connected to your CB1 host. This is, in the first place, an error from the Linux OS that no such device is found.

- Check powers and cables
- Check with the [dmesg procedure](https://klipper.discourse.group/t/how-to-trouble-shoot/6326#linux-dmesg-5) what is “seen” by the operating system

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_[View the full topic](https://klipper.discourse.group/t/suddenly-mcu-unable-to-connect-vzbot-bttcb1/23453)._