Troubleshooting needs to be done in a systematic manner.
1, You indicate that you have power at the outlet. If you are using an extension cord, check to be sure you have power at the end of the extension cord into which the Traeger power cord is plugged.
2. Check to see if the Traeger cord is securely plugged into the bottom of the pellet hopper. This design helps with water resistance, but if you tug on the cord it can come unplugged from the hopper receptacle. I had this happen a couple of times and now wrap the cord around the leg of the grill a few times to provide strain relief.
3. If you have a voltmeter, you can unplug the Traeger cord from the hopper and check to make sure you have power at the prongs. The plug it in securely.
4. There was a recent post about a grill in which the power switch on the side of the pellet hopper failed. If you have a voltmeter, you can check the switch for an open connection. I have seen multiple reports of this happening. Fortunately, it is a quick, easy, and inexpensive replacement.
5. If you have power at the controller side of the switch, but the controller is still dead, you might have a bad controller. Unlike the switch, replacement is not inexpensive unless you are still within warranty.