Epson TM-U220-i Technical Reference Manual page 69

Initialization procedure
1
Load the paper on the product and turn on the product.
2
Push and hold the push button for 10 seconds or longer.
The following initialization start message is printed.
Press the push button with a thin object such as a tweezers.
Do not turn off the power until the initialization is completed.
3
20 to 25 seconds later, the following message is printed, and a status sheet is
printed out.
Chapter 2 Setup
Push button
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