Dymo LabelWriter SE300 User Manual page 113

= The on/off light will also flash when the printer comes to
the end of a label roll. Load a new roll of labels and the
light should stop flashing.
= If the print quality is poor, the print head might be
temporarily misaligned. Unload and reload the labels, and
try printing again. If this doesn't solve the problem, run a
LabelWriter Cleaning Card (Dymo-CoStar part # 60601)
through the print path to remove residues from the print
head and rollers. Also, make sure that you are not using
paper that has been exposed to sunlight for a prolonged
period of time.
Check the Connections
If the self-test is successful but the LabelWriter still will not
print, do the following:
= Check to be sure you have selected the correct serial port
in your software. Confirm that your serial port is set to
9600 baud, no parity, 8 data bits, 1 stop bit.
= Check to see if the printer cable is properly connected.
Refer to Chapter 1 and your computer's documentation if
you need help.
B-109