I purchased a Roku Premiere on Saturday, 5/23/20. I received the "low power" notice the next day. I can't use the supplied USB cord because it's too short but, I am using the power cord.
If I had a problem with something the next day I'd take it back and get another one.
I'd have to agree with @boogernose for something that is acting odd so quickly. But when you say you are using a power cord, are you connecting the cord to a USB port on the TV or some other device, or are you using the power cube included with the Roku and plugged directly into a wall outlet? If you are not using the Roku power cube and plugged directly into the wall, that might be your issue.
I agree with both of you! I've already contacted Best Buy but, unfortunately they don't have any replacements in stock.
*I'm using the power cord included with Roku.
Thanks for the update.
Please send me a PM with your Roku account email address, and include the serial number on the Roku device. I'll be able to assist you further from there.
Thanks,
Danny
Done!