Fujitsu FI-4860C Operator's Manual page 18

Do not install the scanner on unstable surfaces.
Install the scanner on a desk so that none of its parts protrude outside of
the desktop. Also, make sure that the scanner is installed on a flat, level
surface.
Do not install the scanner on unstable surfaces. Install the scanner on a
level surface that is free of vibration to prevent it from tilting.
Install the scanner on a strong surface that will support the weight of the
scanner and any other devices on that surface.
Firmly insert the power plug.
Firmly insert the power plug into the power outlet as far it will go.
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