--- title: Endstop issues and how to fix them (BCN3D Sigma) description:     When Sigma gets stuck in home position producing a loud screeching noise. This is a clear sign that you need to check the endstops, maybe one of them is stuck or broken and needs replacing.   Note --- [Skip to content](https://support.bcn3d.com/knowledge/endstop-issues-bcn3d-sigma#main-content) - [English](https://support.bcn3d.com/knowledge/endstop-issues-bcn3d-sigma) - [Español](https://support.bcn3d.com/es/knowledge/endstop-issues-bcn3d-sigma) English Show submenu for translations [Contact support](https://support.bcn3d.com/knowledge/kb-tickets/new?hsLang=en) [Customer portal](https://support.bcn3d.com/repair-service?hsLang=en) ![knowledge-base-header-bcn3d-logo.png\]](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Header/knowledge-base-header-bcn3d-logo.png?height=40&name=knowledge-base-header-bcn3d-logo.png) - [Default HubSpot Blog](https://blog.bcn3d.com/) Open main navigation Close main navigation - [Default HubSpot Blog](https://blog.bcn3d.com/) - - [English](https://support.bcn3d.com/knowledge/endstop-issues-bcn3d-sigma) - [Español](https://support.bcn3d.com/es/knowledge/endstop-issues-bcn3d-sigma) English Show submenu for translations - [Contact support](https://support.bcn3d.com/knowledge/kb-tickets/new) - [Customer portal](https://support.bcn3d.com/repair-service) - [BCN3D forum](https://www.bcn3d.com/community/) [BCN3D forum](https://www.bcn3d.com/community/) Hello. How can we help you? - There are no suggestions because the search field is empty. 1. [Knowledge base - BCN3D](https://support.bcn3d.com/knowledge?hsLang=en) 2. [Sigma + Sigmax](https://support.bcn3d.com/knowledge/sigma-sigmax?hsLang=en) 3. [Troubleshooting](https://support.bcn3d.com/knowledge/sigma-sigmax?hsLang=en#troubleshooting) # Endstop issues and how to fix them (BCN3D Sigma)   | **Tools** |   | | --- | --- | | ![allen-icon](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Tools/allen-icon.png?width=21&name=allen-icon.png) | > Allen key 2.5mm  | | ![allen-2-icon](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Tools/allen-2-icon.png?width=16&name=allen-2-icon.png) | > Allen key 2mm | | ![cutter](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Tools/cutter.png?width=74&name=cutter.png) | > Cutter | ---   When Sigma gets stuck in home position producing a loud screeching noise. This is a clear sign that you need to check the endstops, maybe one of them is stuck or broken and needs replacing.   **Note: **It's possible that you need to disassemble the endstops from the printer in order to check them properly, in the end of this article there are links with instructions that will help you in the process.    Below you can see where the printer’s endstops are placed: ![endstops-sigma](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Sigma-Sigmax%20R19/endstop%20issues/endstops-sigma.png?width=600&name=endstops-sigma.png) The most common endstop related issues are: **1: Cable connection issues**. Check that the endstop cable is properly connected to the driver or extruder board in case of the Z axis one. | ![endstop-connection-check-2](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Sigma-Sigmax%20R19/endstop%20issues/endstop-connection-check-2.png?width=391&name=endstop-connection-check-2.png) | ![endstop-connection-check-1](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Sigma-Sigmax%20R19/endstop%20issues/endstop-connection-check-1.png?width=391&name=endstop-connection-check-1.png) | | --- | --- |   **2: (Usually in the Z endstops) Bent flat flexible cable.** Check if the hotend flat cable is bent on the extruder board connection. If it is, you can straighten it manually and do a bed calibration to check if the problem continues. | ![](https://support.bcn3d.com/hubfs/image-png-Aug-04-2020-10-01-11-55-AM.png) | ![](https://support.bcn3d.com/hubfs/image-png-Aug-04-2020-10-01-25-31-AM.png) | | --- | --- |   **3: Jammed switch.** It can be unblocked using a cutter or a needle. ![jammed-endstop](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Sigma-Sigmax%20R19/endstop%20issues/jammed-endstop.png?width=600&name=jammed-endstop.png) **4: Broken endstop.** Replace the endstop with a new one, see the parts list in this same article. ![broken-endstop](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Sigma-Sigmax%20R19/endstop%20issues/broken-endstop.png?width=600&name=broken-endstop.png)   **Conclusions: ** If none of the articles steps works, you will have to replace the Endstop. You can learn how to do that in the following articles: [How to replace the X Endstop](https://support.bcn3d.com/knowledge/change-x-endstop-bcn3d-sigma?hsLang=en) [How to replace the Y Endstop](https://support.bcn3d.com/knowledge/y-endstop-bcn3d-sigma?hsLang=en)  [How to replace the Z Endstop](https://support.bcn3d.com/knowledge/change-z-endstop-bcn3d-sigma?hsLang=en)    #### [Forum Community](https://support.bcn3d.com/knowledge/bcn3d-forum-community?hsLang=en) This article doesn't fix your issue? Check out our [**forum community**](https://support.bcn3d.com/knowledge/bcn3d-forum-community?hsLang=en) for more info about this.   It's important to keep your printer in good shape to make the most out of it. In this chart, you can find a list of the extruder maintenance procedures and how frequently these should be done. [Maintenance Plan (BCN3D Sigma)](https://support.bcn3d.com/knowledge/maintenance-plan-bcn3d-sigma?hsLang=en)   ![bcn3d-recycle](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Tools/bcn3d-recycle.png?width=27&name=bcn3d-recycle.png)  Take your e-waste to a certified recycler. [Check how we do it in BCN3D.](https://support.bcn3d.com/knowledge/environment-bcn3d?hsLang=en)   | **Parts** | | Buy these parts | | --- | --- | --- | | ![x-endstop-component](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Components/x-endstop-component.png?width=107&name=x-endstop-component.png) | BCN3D Sigma/Sigmax X endstop | [SKU 10941](https://www.bcn3d.com/es/product/endstop-2/) | | ![x-endstop-component](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Components/x-endstop-component.png?width=107&name=x-endstop-component.png) | BCN3D Sigma/Sigmax Y endstop | [SKU 10942](https://www.bcn3d.com/es/product/endstop-2/) | | ![x-endstop-component](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Components/x-endstop-component.png?width=107&name=x-endstop-component.png) | BCN3D Sigma/Sigmax Z endstop | [SKU 10943](https://www.bcn3d.com/es/product/endstop-2/) |   | --- #### RELATED ARTICLES | | --- | | [![check flat cable eng](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Related%20Articles%20English/check%20flat%20cable%20eng.png?width=600&name=check%20flat%20cable%20eng.png)](https://support.bcn3d.com/knowledge/check-flat-cable-connections-bcn3d-sigma?hsLang=en)   | [![check mainboard fuse eng](https://support.bcn3d.com/hs-fs/hubfs/Knowledge%20base/Related%20Articles%20English/check%20mainboard%20fuse%20eng.png?width=600&name=check%20mainboard%20fuse%20eng.png)](https://support.bcn3d.com/knowledge/mainboards-fuse-bcn3d-sigma?hsLang=en)   | | --- | --- | | **You can help improve the BCN3D Knowledge Base.** If you feel there are guides that we are missing or you found any error, please use this form to report it. **[Report form](https://share.hsforms.com/1F7t1sBuOQyWlAeRwwFSjgQ3fec5)** :) | | --- | - 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