# Anycubic Kobra Plus -- Hotend and MCU fan always on

**URL:** <https://klipper.discourse.group/t/anycubic-kobra-plus-hotend-and-mcu-fan-always-on/14601>\
**Category:** General Discussion\
**Created:** [March 2, 2024, 6:35pm UTC](https://klipper.discourse.group/t/anycubic-kobra-plus-hotend-and-mcu-fan-always-on/14601 "2024-03-02T18:35:30Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![EDACerton](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/edacerton/32/4399_2.png) [@EDACerton](https://klipper.discourse.group/u/EDACerton)\
**Post date:** [March 2, 2024, 6:35pm UTC](https://klipper.discourse.group/t/anycubic-kobra-plus-hotend-and-mcu-fan-always-on/14601/1 "2024-03-02T18:35:30Z")

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### Basic Information:

Printer Model: Anycubic Kobra Plus  
 MCU / Printerboard: Trigorilla\_Pro\_A\_V1.0.4

### Describe your issue:

```auto
[controller_fan controller_fan]
pin: PA14
heater: heater_bed

[heater_fan heater_fan]
pin: PA13

```

On my printer, the hotend and MCU fans both go to 100% as soon as the printer starts up, regardless of the commanded status. Anycubic publishes the Marlin config for the stock firmware, so I know that the pins are correct:

```auto
//
// Fans
//
#define FAN_PIN PB9 // model fan
#define FAN1_PIN PA13 // auto fan for E0
#define FAN2_PIN PA14 // controller fan
#define CONTROLLER_FAN_PIN FAN2_PIN
#define FAN_SOFT_PWM

```

(Source: [Kobra\_Plus/source/Marlin/src/pins/stm32f1/pins\_AC\_TRI\_F1\_V1.h at master · ANYCUBIC-3D/Kobra\_Plus · GitHub](https://github.com/ANYCUBIC-3D/Kobra_Plus/blob/master/source/Marlin/src/pins/stm32f1/pins_AC_TRI_F1_V1.h) )

Does anyone have any ideas about why the fans don’t respond to control with Klipper?

---

<div class="post-metadata">

**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:** [March 2, 2024, 7:29pm UTC](https://klipper.discourse.group/t/anycubic-kobra-plus-hotend-and-mcu-fan-always-on/14601/2 "2024-03-02T19:29:46Z")

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Hello @EDACerton !

![grafik](https://global.discourse-cdn.com/free1/uploads/klipper/original/2X/c/c4bef3f8856840c2ca7e2723b37af2101585701e.png)

I’m missing that line that asks for the klippy.log.

Please attach it to your **next post**.

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<div class="post-metadata">

**Author:** ![EDACerton](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/edacerton/32/4399_2.png) [@EDACerton](https://klipper.discourse.group/u/EDACerton)\
**Post date:** [March 2, 2024, 11:31pm UTC](https://klipper.discourse.group/t/anycubic-kobra-plus-hotend-and-mcu-fan-always-on/14601/3 "2024-03-02T23:31:50Z")

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[klippy.log](https://klipper.discourse.group/uploads/short-url/7lWVyVNmANFexTYj7ge1FtDEgIX.log) (40.0 KB)

---

<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:** [March 3, 2024, 5:31pm UTC](https://klipper.discourse.group/t/anycubic-kobra-plus-hotend-and-mcu-fan-always-on/14601/4 "2024-03-03T17:31:16Z")

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You have not configured any conditions for these fans.  
See

- [heater\_fan](https://www.klipper3d.org/Config_Reference.html#heater_fan)
- [controller\_fan](https://www.klipper3d.org/Config_Reference.html#controller_fan)

---

<div class="post-metadata">

**Author:** ![EDACerton](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/edacerton/32/4399_2.png) [@EDACerton](https://klipper.discourse.group/u/EDACerton)\
**Post date:** [March 3, 2024, 6:00pm UTC](https://klipper.discourse.group/t/anycubic-kobra-plus-hotend-and-mcu-fan-always-on/14601/5 "2024-03-03T18:00:07Z")

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Right… I’m expecting the default behavior for both fans (heater runs when heater enabled, controller runs when steppers enabled).

Klipper shows the desired status, but the actual status doesn’t match (e.g., when I start the printer, the hotend fan says it is off, but the fan starts running at 100%. Same with the controller fan.)

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<div class="post-metadata">

**Author:** ![EDACerton](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/edacerton/32/4399_2.png) [@EDACerton](https://klipper.discourse.group/u/EDACerton)\
**Post date:** [March 4, 2024, 4:50am UTC](https://klipper.discourse.group/t/anycubic-kobra-plus-hotend-and-mcu-fan-always-on/14601/6 "2024-03-04T04:50:03Z")

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Adding the solution for folks who might find this later:

I updated the MCU, and now the fans respond to control as expected.

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<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:** [April 3, 2024, 2:50pm UTC](https://klipper.discourse.group/t/anycubic-kobra-plus-hotend-and-mcu-fan-always-on/14601/7 "2024-04-03T14:50:43Z")

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