# Enabling saving thumbnail images on the MiniSeq

Thumbnail images on the MiniSeq may be useful when troubleshooting run quality issues or for determining clustering efficiency. By default, the setting to save thumbnail images is **not enabled** on the MiniSeq, as the images increase run folder size and can cause runs to crash due to the increased strain on the hard drive. However, if the user would like to enable saving of thumbnail images for diagnostic purposes, follow the guidance below.

1. Close MiniSeq Control Software (MnCS).
2. Locate the following file:

* Windows 7:
  * C:\Illumina\MiniSeq Control Software\InstrumentShell.MiniSeqControlSoftware.Options.cfg
* Windows 10:
  * C:\ProgramData\Illumina\MiniSeq Control Software\InstrumentShell.MiniSeqControlSoftware.Options.cfg
    * **The ProgramData folder may be hidden;** to un-hide files, select the View tab in the file explorer window and make sure “Hidden items” is checked.

3. Make a copy of the file, rename it to "InstrumentShell.MiniSeqControlSoftware.Options.BACKUP.cfg", and save it as a backup.
4. Open the original file and locate this line:

* ![](/files/n2kOExYM6FxpzLIiij6Z)

5. Change **false** to **true**, and make sure that no additional characters or spaces are added or deleted.
6. Save the changed file.
7. Power cycle the instrument.

* For further information, search for Knowledge Base article **How to Power Cycle the MiniSeq**.

The thumbnail images, when saving is enabled, are saved to: \[Run Folder]\Thumbnail\_Images\L001\C\[X.1] where X refers to the cycle number.

After following the above steps, the next run will save thumbnail images for each cycle.

Enabling this option does not retroactively add thumbnails to past runs.

To disable Thumbnail Images, follow the above steps and change the argument back from **true** to **false** in step 5.

**Note**: Thumbnail Images will only be saved for Tiles 1 and 6 if enabled.

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| *For any feedback or questions regarding this article (Illumina Knowledge Article #2032), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000002032%20-%20Instrumentation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |


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