# Troubleshooting Cycle 1 Error, Camera Disabled, Failed to Detect Clusters on the NextSeq 500/550

This notification indicates that the NextSeq 500/550 is unable to detect clusters at cycle 1 for the reported cameras, lanes, and/or surfaces. A large number of sections disabled may be reported.

Potential causes for cycle 1 errors include instrument, sequencing consumables, or library (design/custom primers/quantification/denaturation) factors.

* If the run stops at Cycle 1 and Lanes 1/3 show **low** cluster density (no focus images for Lanes 2/4), this is likely a clustering failure; follow the troubleshooting steps below (to troubleshoot the instrument, flow cell, and library).
* If the run stops at Cycle 1 and Lanes 1/3 show **good** cluster density but Lanes 2/4 do not, this shows that the library clustered successfully; troubleshoot this as a flow cell or instrument issue (there is no need to troubleshoot the library in the troubleshooting steps below).

**Example of error messages:**\
![](https://761066130-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FGM9W2DuBTgEXv1ClCm8H%2Fuploads%2Fgit-blob-d9353da3c7e48f11ec41f0e9279a2817d427a9f0%2Fimage1.jpg?alt=media\&token=04e134e8-aeb6-42cb-a495-1e2b3e4130ca)

**The following message may also be present:**\
![](https://761066130-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FGM9W2DuBTgEXv1ClCm8H%2Fuploads%2Fgit-blob-f64fa59bf43bd0bccf7a364cc8886becb4cee6de%2Fimage2.jpg?alt=media\&token=75a89254-908b-4b3c-ab09-4c5ee501c541)

**Note 1:** It is not recommended to save the flow cell for rehybridization following a cycle 1 cameras disabled error. See [NextSeq 500 and NextSeq 550 Sequencing Systems Product Documentation](https://support-docs.illumina.com/IN/NextSeq_550-500/Content/IN/NextSeq/RehybWorkflow_Intro_fNS.htm) for more information.

**Note 2**: The instrument may give an option to purge reagents after the run ends. This option will proceed with purging consumables and then performing the automatic post-run wash. The purging process can take a few hours (especially for a cycle 1 error when most of the reagents are still in the reagent cartridge), to initiate troubleshooting immediately, bypass the reagent purge.

**Troubleshooting steps:**

1. Acknowledge the error message. The flow cell cannot be saved. Illumina does not require the purge. Perform the post-run wash.
2. Power cycle the instrument.\*
3. Perform System Check\* with a used flow cell. Illumina recommends using a high output flow cell (a high output flow cell is recommended since mid-output flow cells can have false flow rate failures).
4. Review the Focus Images:
   1. Focus images are saved even if run stopped at cycle 1 and can be found at D:\Illumina\ NextSeq Control Software Temp\[Run\_Folder]\Images\Focus\L00X\C1.1
   2. Images may be present for all 4 lanes or lanes 1/3 only.
   3. It is normal for many images to be black, these images are taken at different heights to find focus.
   4. See Knowledge Base Article **Focus images on MiniSeq\*\*\*\*and NextSeq 500/550** for more information.
5. If a clustering issue is suspected, troubleshoot the library:
   1. Review Library type/design.
   2. Library quantification.
   3. Denaturation steps.
   4. Use or requirement of custom sequencing primers.

\*For further information, search for Knowledge Base articles **How to Perform a NextSeq 550 Power Cycle** and **How to Perform a NextSeq 550 System Check**.

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| *For any feedback or questions regarding this article (Illumina Knowledge Article #1681), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000001681%20-%20Instrumentation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |