# Troubleshooting laser coolant temperature errors on the NovaSeq 6000

**Background**

The following errors may occur during a NovaSeq 6000 run, though the run may proceed:

* Laser coolant temperature is out of range.
* The coolant might not be reaching the optical compartment.
* The coolant might not be reaching the flow cell holder.

**Troubleshooting Actions**

* Check the lab temperature.
  * Elevated lab temperature or other nearby equipment that increases room temperature can cause these errors. The recommended temperature range for a NovaSeq 6000 is 19°C to 25°C (22°C ±3°C). For more information, refer to [NovaSeq Site Prep Guide](https://support.illumina.com/downloads/novaseq-site-prep-guide-1000000019360.html).
* Power cycle the instrument. For additional details, see for Knowledge Base article [How to Power Cycle the NovaSeq 6000 System](https://knowledge.illumina.com/instrumentation/novaseq-6000/instrumentation-novaseq-6000-reference_material-list/000002470).
  * If the instrument initializes successfully after the power cycle, proceed to the next run.
  * If the lab temperature is within the recommended range and the error reoccurs after a power cycle, collect the **CompressedLogs.zip** located in C:\ProgramData\Illumina\NovaSeq\NovaSeqTemp\[run folder]\Logs\CompressedLogs from the affected Run(s) and contact [Illumina Technical Support](https://www.illumina.com/company/contact-us.html) for the next steps.

**Note**: System checks will **not** be helpful in troubleshooting these types of error messages.

\
\
\ <br>

|                                                                                                                                                                                                                                                                                                                                                                        |
| :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------: |
| *For any feedback or questions regarding this article (Illumina Knowledge Article #3300), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000002470%20-%20Instrumentation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |