@Malayahisnotok
For the power outlet, try using a USB charging adapter that is 5volts. 1 amp rated. (may also want to try a different micro USB charging cable in case the power cable provided with your device is defective).
Try Factory Resetting the device (press and hold in Reset button for 30+ seconds.) May have to do this reset procedure more than once).
If none of the above work, then you may just have a defective device and should return for a new one. If purchased from Roku, use the warranty procedure. https://support.roku.com/article/208757058.
If purchased elsewhere, just contact or return to the seller.
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
Insignia RokuTV, Ultra 4660, 4802, 4850, Premiere+ 3921, Express 4k+ 3941, Streambar 9102