UMAX Technologies Astra 4400 Operation Manual page 31

Cleaning
Regularly cleaning the object glass will ensure that dirt or smudges will not
reduce the quality of your scanned images. Before you clean the glass, make
sure the scanner is turned off and the power cord is unplugged.
Clean the object glass and document cover with a soft damp cloth and a
mild detergent or alcohol.
Warning: Do not spray cleaning fluids directly on the object
glass. Spraying the liquid directly on the glass may
cause the liquid to penetrate the seams around the glass
and contaminate the mirrors and lenses inside the
scanner. Please be sure you spray the liquid on the
cleaning cloth and then wipe the glass clean.
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