Digital BW, The Print

> I have a 2450 with which I have been mostly dissapointed.  The
> underside of the glass cannot be cleaned, except by a service
> station ...

It's actually fairly easy to do it yourself (the hard part is to
not get it MORE dusty in the process !).  I'll append the
description, originally posted by Ralf Radermacher.

Good luck, John

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As already suggested by others, the upper part of the housing
including
the glass plate (from now on called upper frame, forRadermacher the
purpose of this
description) is fastened by the two screws down in the holes holding
the
transparency unit.

Before proceding, do have a look through the glass plate at the area
just behind the button of the power switch, in the front left corner
of
the scanner. You'll see a little PC board and a connector with a few
wires going towards the upper frame because the actual power switch is
fastened to and will come off with the upper frame.

Now, undo the two screws, lift the upper frame at the rear, and slide
it
slightly forward (about 10 mm) to disengage it at the front side. Now,
swing the upper frame to the left, as seen from the front of the
scanner, and disconnect the little connector described above. The
upper
frame is now completely free and can be cleaned using either alcohol
or
a glass cleaning product.

Re-assemble in reverse order (don't forget the cable connector).

May I add that the whole operation should be carried out in a location
with as little dust in the air as possible or you'll end up
introducing
more dirt into the unit than you wanted to remove in the first place.
In
most domestic environments this would be the bathroom. Really, no
joke.

Blow out the inside of the upper frame with dried air before
re-fitting
it. 

Oh, one more thing: Here's a little trick for getting the screws back
into the thread they've cut themselves in the plastic material when
the
scanner was first assembled: instead of fastening them right away
apply
very light pressure and turn the screwdriver counter-clockwise (as if
you wanted to undo them) until you notice a slight 'click'. Now, turn
clockwise to fasten the screw. This trick works for all those many
instances of screws in plastic material. It avoids mashing up the
plastic inside the hole and ending up with a screw that can't be
tightened anymore.