# Guidance regarding light seen from the DRAGEN v4 power supply when an unstable power cord is used

Users of DRAGEN v4 servers may notice a bright light when the power cord for the server power supply is shaken during use; an example is shown below.

![](/files/PML27jZGjzHBpORUIV4H)

This light is from the surge absorber within the power supply when the AC power cord connection is unstable.

![](/files/8O3uDry8LBEW3voTb0bW)

The surge absorber converts high-voltage surges into light energy and releases it. While the light may be mistaken for sparks or an arc, this discharge phenomenon is normal and does not pose any danger to users.

Since this light only appears when the power cord is not properly connected to the server power supply, it is critical to make sure the AC power cord is securely connected before supplying AC power for normal operation.

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| *For any feedback or questions regarding this article (Illumina Knowledge Article #9610), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000009610%20-%20Software%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |


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