Its recommended to charge HP Sprocket for at least 30 minutes using a power source with at least 2 AMPs, such as a wall adapter or USB-capable power strip. If the printer still doesn't power on after sufficient charge, then try resetting the printer. Here is how to do it:
1.) Remove the paper cover.
2.) Locate the Reset button.
3.) With a paperclip or pin, press and hold the Reset button for 3 seconds.
The printer resets.
4.) Replace the paper cover, and then turn on the printer.
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