First Test

The first test you should do is to just make sure that the printer is running and you have the power wired up right.

First up, pull the little plastic tab up top to open up the paper holder. Then insert a roll of 57.5mm (2 1/4 inches) thermal paper into the bay as shown below.

Make sure that the paper doesn't bind or stick in the bay, it should rotate freely.

 

As previously described, power the printer using a 5V to 9V 1.5A or higher power supply, such as wiring up a 2.1mm DC power jack:

Hold down the button on the top of the printer (or on the control board) while plugging in the power. You should see a receipt print out showing the font table and some diagnostics.

There is no button on the printer guts (#2753). You will need to attach one to J1 or short it manually.
The Green or Red LED could be blinking when the printer is powered. It will not necessarily be on steady!

If you don't get a printout, check that the paper is inserted correctly and not binding, that the power is correctly wired, power supply is plugged in, etc. Then try again, holding down the button when connecting power.

Note the baud rate on the test page. This may be 19200 or 9600. We'll need this number later:

Some printer guts (#2753) do not have a self test.
If no baud rate prints out, try using 9600 as the default.
This guide was first published on Sep 02, 2012. It was last updated on Sep 02, 2012. This page (First Test) was last updated on Jan 22, 2019.