Cleaning The Print Head - Epson TM-T90 Manuel D'utilisation

The roll paper cover will not open
Turn on the printer and remove the cutter cover. To remove the
cover, use a tool such as a screwdriver, and insert it into one of the
slots indicated by a circle in the illustration below and push the
cover upward. After removing the cutter cover, use a ballpoint pen
or tweezers to turn the knob in the direction indicated by the arrow
until you see a triangle in the opening.

Cleaning the Print Head

After printing, the print head can be very hot. Be careful not to touch it
and to let it cool before you clean it. Do not damage the print head by
touching it with your fingers or any hard object.
Turn off the printer, open the roll paper cover, and clean the
thermal element of the print head with a cotton swab moistened
with an alcohol solvent (ethanol or IPA).
Epson recommends cleaning of the thermal head periodically
(generally every three months) to maintain receipt print quality.
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CAUTION:
TM-T90 User's Manual 11
English