# Mcu 'rpi': Unable to connect after update and reinstall

**URL:** <https://klipper.discourse.group/t/mcu-rpi-unable-to-connect-after-update-and-reinstall/14016>\
**Category:** General Discussion\
**Created:** [February 10, 2024, 6:54pm UTC](https://klipper.discourse.group/t/mcu-rpi-unable-to-connect-after-update-and-reinstall/14016 "2024-02-10T18:54:25Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![mtbmarkus](https://avatars.discourse-cdn.com/v4/letter/m/59ef9b/32.png) [@mtbmarkus](https://klipper.discourse.group/u/mtbmarkus)\
**Post date:** [February 10, 2024, 6:54pm UTC](https://klipper.discourse.group/t/mcu-rpi-unable-to-connect-after-update-and-reinstall/14016/1 "2024-02-10T18:54:25Z")

</div>

### Basic Information:

Printer Model: VZbot 4wd  
 MCU / Printerboard: octopus v1.1  
 `klippy.log`  
[moonraker (7).log](https://klipper.discourse.group/uploads/short-url/eUn0KQOYHXvq7DC29EBTAiKXEtu.log) (74.2 KB)  
[klippy (17).log](https://klipper.discourse.group/uploads/short-url/sxgMX4VXVS7YFVBkhnDwqCHTHch.log) (211.8 KB)

### Describe your issue:

…  
After a update i was not able to reach my mcu.  
Now i have reinstalled evertythinh but still the same message mcu ‘rpi’: Unable to connect. I connect via usb and have RPI z2w

installed klipper firmware from btt github - same  
installed the firmware from makemenu config - same  
Installed new mainsail os - same

---

<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:** [February 10, 2024, 6:57pm UTC](https://klipper.discourse.group/t/mcu-rpi-unable-to-connect-after-update-and-reinstall/14016/2 "2024-02-10T18:57:58Z")

</div>

The Klipper “host-mcu” process according to [RPi microcontroller - Klipper documentation](https://www.klipper3d.org/RPi_microcontroller.html) seems not correctly installed or has some other issues.

Also refer to [Klipper-mcu Service Fails to Start](https://klipper.discourse.group/t/klipper-mcu-service-fails-to-start/12219). The issue outlined there might not be your issue, but it should give you some troubleshooting hints.

---

<div class="post-metadata">

**Author:** ![mtbmarkus](https://avatars.discourse-cdn.com/v4/letter/m/59ef9b/32.png) [@mtbmarkus](https://klipper.discourse.group/u/mtbmarkus)\
**Post date:** [February 10, 2024, 7:02pm UTC](https://klipper.discourse.group/t/mcu-rpi-unable-to-connect-after-update-and-reinstall/14016/3 "2024-02-10T19:02:49Z")

</div>

Thank you!  
Everything works now when i installed RPi microcontroller 🙂

---

<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/klipper/original/1X/64419bf2aac6639e6ef5cef200dcd456b0a01ac3.png) [@system](https://klipper.discourse.group/u/system)\
**Post date:** [March 12, 2024, 5:02am UTC](https://klipper.discourse.group/t/mcu-rpi-unable-to-connect-after-update-and-reinstall/14016/4 "2024-03-12T05:02:54Z")

</div>

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.