Xerox 4090 - Manual (Page 95)

PRINTER MAINTENANCE
3. To clean the EOT/BOT sensor, lightly moisten a swab with the
head cleaning solution. As the figure below shows, use the
swab to remove any dirt or oxide that may have collected on
the sensor surfaces and reflective strip.
4. To clean the tape cleaner, use the swab prepared for the
EOT/BOT sensor. Carefully go over the tape cleaner blades
with it to remove any dirt that may have collected.
WARNING: The blades are razor sharp. Keep your fingers
away from them.
XEROX 4050/4090/4450/4650 LPS OPERATOR GUIDE 6-7