# 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:**\
**The following message may also be present:**\
**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**.
\
\
\
| |
| :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------: |
| *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)*.* |
---
# Agent Instructions: Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
GET https://knowledge.illumina.com/instrumentation/nextseq-500-550/instrumentation-nextseq-500-550-troubleshooting-list/000001681.md?ask=
```
The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.