# Step 4: Connect the power source and verify power to your Outposts server
To complete power up, you attach the NSK, connect the server to a power source, and verify that the server has powered on. Consider the following information about powering the server:
+ The server functions with one power source, but AWS recommends you use two power sources for redundancy.
+ Connect the power cables before you connect the network cables.
+ Use the pair of C13 outlet/C14 inlet power cables to connect the server to a power supply on the rack. If you're not using the C14 inlet power cable to connect the server to a power supply on the rack, you must provide adapters for the C14 inlets that connect to a power source.
**Topics**
+ [Attach NSK](power-attach-nsk.md)
+ [Power on](power-on.md)
+ [Check the NSK Power LED](power-check-led.md)
# Attach the NSK to your Outposts server
You must attach the NSK to the server so it can decrypt data on the server during operation.
**Important**
The side of the NSK has instructions on how to destroy the NSK. Do not follow those instructions now. Follow those instructions only when returning the server to AWS, to [cryptographically shred the data](https://docs.aws.amazon.com/outposts/latest/server-userguide/outpost-maintenance.html#outpost-server-cryptographically-shred-data) on the server.
If you are installing multiple servers at the same time, ensure that you do not mix up the NSKs. You must attach the NSK to the server that it shipped with. If you use a different NSK, the server will not boot up.
**To attach the NSK**
1. On the front right side of the server, open the NSK compartment.
The following image shows the NSK attached to a 2U server.
![\[An image of an NSK attached to a 2U server.\]](http://docs.aws.amazon.com/outposts/latest/install-server/images/ru2-attach-nsk.png)
The following image shows the NSK attached to a 1U server.
![\[An image of an NSK attached to a 1U server.\]](http://docs.aws.amazon.com/outposts/latest/install-server/images/cubscout-nsk.png)
1. Ensure that the serial number (SN) on the NSK matches the SN on the bezel pull-out tab of the NSK compartment on the server.
The following image shows the SN number on the NSK and bezel pull-out tab:
![\[Image shows SN of NSK matches the SN of the bezel pull-out tab.\]](http://docs.aws.amazon.com/outposts/latest/install-server/images/sn-nsk.png)
1. Fit the NSK into the slot.
1. Hand tighten using the thumbscrew or tighten with a screwdriver (0.7 Nm / 0.52 lb-ft) until snug. Do not use power tool as it might over-torque and damage the NSK.
The following image shows the location of the thumbscrew.
![\[An image of an NSK showing the location of the thumbscrew.\]](http://docs.aws.amazon.com/outposts/latest/install-server/images/nsk-thumbscrew.png)
The following image shows the type of screwdriver you can use to attach the NSK to the server.
![\[Shows the type of screwdriver you can use to attach the NSK to the server. Also shows the type of screwdriver you can't use.\]](http://docs.aws.amazon.com/outposts/latest/install-server/images/outpost-nsk-attach.jpg)
# Connect the power source and verify power to your Outposts server
Use the following procedures to connect your Outposts server to its power source and then verify that the server has powered on.
**To connect the server to power**
1. Locate the pair of C13/C14 power cables that came with the server.
1. Connect the C14 end of both cables to your power source.
1. Connect the C13 end of both cables to the ports on the front of the server.
**To verify that the server has power**
1. Verify that you can hear the server running.
**Tip**
The noise level goes down after the server provisions itself.
1. Verify that the LED power lights above the power ports are lit.
The following image shows the LED power lights on a 2U server
![\[An image of LED power lights on a 2U server.\]](http://docs.aws.amazon.com/outposts/latest/install-server/images/ru2-power-led.png)
The following image shows the LED power lights on a 1U server
![\[An image of LED power lights on a 1U server.\]](http://docs.aws.amazon.com/outposts/latest/install-server/images/led-on-cubscout.png)
# Check the Power LED on the Atlas 3.0. NSK
AWS Outposts supports two versions of NSK: Atlas 2.0 and Atlas 3.0. Both NSK versions have a RGB **Status** LED. In addition, the Atlas 3.0 has a green **Power** LED. This step is only for the Atlas 3.0 NSK.
The following image shows the location of the LEDs on the Atlas 2.0 and Atlas 3.0 NSKs:
![\[An image of the Atlas 2.0 and 3.0 NSKs with the RGB Status LED on each NSK and the green Power LED on the Atlas 3.0.\]](http://docs.aws.amazon.com/outposts/latest/install-server/images/nsk-led-status.png)
If you have the Atlas 2.0 NSK, skip to the next step, [Step 5: Connect your Outposts server to your network](install-network.md) because this version of the NSK only has the RGB Status LED which you must check after the Outposts server is provisioned and activated.
If you have the Atlas 3.0 NSK, check the green Power LED:
+ If the green light is on, the NSK is correctly connected to the host and has power. You can proceed to the next step.
+ If the green light is off, the NSK is not correctly connected to the host or/and has no power. Contact Support.