# Interpretation Help needed: MCU 'mcu' shutdown: Timer too close **URL:** \ **Category:** General Discussion\ **Created:** [April 25, 2024, 12:26pm UTC](https://klipper.discourse.group/t/interpretation-help-needed-mcu-mcu-shutdown-timer-too-close/16022 "2024-04-25T12:26:19Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![HowlingCoder](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/howlingcoder/32/11553_2.png) [@HowlingCoder](https://klipper.discourse.group/u/HowlingCoder)\ **Post date:** [April 25, 2024, 12:26pm UTC](https://klipper.discourse.group/t/interpretation-help-needed-mcu-mcu-shutdown-timer-too-close/16022/1 "2024-04-25T12:26:19Z")
### Basic Information: Printer Model: Ender 3 V2 Max Neo MCU / Printerboard: Creality Silent Board 4.2.7 Host / SBC: Raspberry Pi 3A klippy.log [klippy.log](https://klipper.discourse.group/uploads/short-url/tOwzMm44jvr5VswvZwsyBN1fCEf.log) (2.1 MB) ### Describe your issue: I recently switched from Marlin to Klipper and everything works fine besides I’m getting several mcu shutdowns. Everything, including the SD Card, is fairly new and worked on the Marlin setup without a charm. When does this happen: Usually with longer prints, but also random for short prints. Shortly after start of the print (10-15 minutes) as well as mid print or close to the end. Haven’t found a pattern yet. What I also did: Checked the Raspberrys Voltage (vcgencmd get\_throttled gave me throttled=0x0) Reflashed Firmware and updated everything Try to find something in the Klipper log Cried Edited the background task like suggested here [Link](https://klipper.discourse.group/t/mcu-mcu-shutdown-timer-too-close-on-voron-2-4/8758/6) Things I didn’t do Unplugged the Webcam (since I need it for my monitoring and really won’t like to go without. Furthermore I actually want to upgrade to a touchscreen next month) Bought new hardware (I want to make sure that there are issues with my hardware before trying to find another raspberry or sth similar) Since I’m fairly new to Klipper I hope you can help me interpreting my scenario. Thanks in advance! Max ---
**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 25, 2024, 12:37pm UTC](https://klipper.discourse.group/t/interpretation-help-needed-mcu-mcu-shutdown-timer-too-close/16022/2 "2024-04-25T12:37:51Z")
Hello @HowlingCoder ! You may have a look here: > [@Timer too close](https://klipper.discourse.group/t/timer-too-close/6634): > > Timer too close Background A “Timer too close” error occurs when the MCU is asked to schedule an action at a time that is already in the past. This typically results from delayed communication between the host and the MCU - for instance, if the host was busy or the message was blocked en route. warning Important: Klipper can identify what command was too late, but cannot determine why the delay occurred. The root cause is often external - such as USB congestion from a webcam or high system … ---
**Author:** ![gaolst](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/gaolst/32/10026_2.png) [@gaolst](https://klipper.discourse.group/u/gaolst)\ **Post date:** [April 25, 2024, 3:44pm UTC](https://klipper.discourse.group/t/interpretation-help-needed-mcu-mcu-shutdown-timer-too-close/16022/3 "2024-04-25T15:44:34Z")
Your log indicate that you very often your system have communication issues, your `ready_bytes` constantly recording some bytes are waiting for sending also sometimes you have `upcoming_bytes` jumping - which indicate that some bytes are waiting in MCU for sending. Usually they will go thru with next request and you don’t see ‘Timer too close’ issue, but sometimes they stuck for longer and you are getting ‘Timer too close’ error. When this is happening Stats show that you don’t have some huge load on CPU. As possible solutions you should try to replace your USB cable, USB-to-Serial adapter. It could be your USB port - you can try to plug USB to other port or introduce USB Hub with external power - sometimes this is helping. ---
**Author:** ![HowlingCoder](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/howlingcoder/32/11553_2.png) [@HowlingCoder](https://klipper.discourse.group/u/HowlingCoder)\ **Post date:** [April 26, 2024, 12:16pm UTC](https://klipper.discourse.group/t/interpretation-help-needed-mcu-mcu-shutdown-timer-too-close/16022/4 "2024-04-26T12:16:18Z")
Thanks for your suggestion! I just had a failure without the webcam, but as you mention it there might be something wrong with my USB setup. I’m currently using a hub with an ethernet port (because I had WLAN issues in the past) maybe this mixture is really messing things up. I started a new run without that adapter so the connection from the PI and the printer won’t have any other interferences. Maybe the best idea would be to move to a B variant with ethernet port as well as multiple usb ports 😃 I’ll come back to you after a few testings 🙂 ---
**Author:** ![HowlingCoder](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/howlingcoder/32/11553_2.png) [@HowlingCoder](https://klipper.discourse.group/u/HowlingCoder)\ **Post date:** [May 18, 2024, 5:03pm UTC](https://klipper.discourse.group/t/interpretation-help-needed-mcu-mcu-shutdown-timer-too-close/16022/5 "2024-05-18T17:03:33Z")
Just a quick update: The solution really was to get rid of the USB + Ethernet Adapter. Using solely the remaining USB Port of the Pi and WLAN solved the issue and I never had any trouble since. @gaolst Thank you so much for your help 🙂 ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/klipper/original/1X/64419bf2aac6639e6ef5cef200dcd456b0a01ac3.png) [@system](https://klipper.discourse.group/u/system)\ **Post date:** [June 18, 2024, 3:03am UTC](https://klipper.discourse.group/t/interpretation-help-needed-mcu-mcu-shutdown-timer-too-close/16022/6 "2024-06-18T03:03:59Z")
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