How did the original hinge for the Programming panel work on these Beomasters? The two 2400 I've seen had a kind of sticky, viscous grease that supplied enough friction to prevent the lid from falling closed too quickly. But a later model (the 2000) had an actual spring and a lid release button. Does the 2400 just rely on the user to push the Programming lid up, and the viscosity of the grease to keep it in position? Or is the thick grease the result of an aging process?

The 1900/2400 requires the user to lift the alu lid, it will then lock lightly and stand by itself.
The user will then have to push it gently to unlock it and it will
close slowly due to the grease (kilopoise type) friction, this is normal and age doesn't seem to affect operation much.
Not all lids will close fully if wall mounted, most will stop apprx 1-2mm
prior to fully closed but will hold fully closed nicely if pushed
manually the last bit.

The Beomaster 2000/3000/3300 has a spring to allow the lid to open at the push on the left side of the front. It requires the user to close the lid again manually.
The spring in the lid needs to be changed to a stronger type
if mounted on a wall bracket.

Martin

Thanks for the info! Both the 2400's I've seen seem to have very "goopy" (klæbrig) grease, so I wondered if it had just aged poorly. Is it normal for the grease to be seen on the hinge when open? Looks like a nasty experience if you touched it by mistake... but I wonder if these two sets had some other kind of improper lubricant added in at a later point.

It is normal for the grease to be extremely gooey and not uncommon to see it creep around corners.
Especially the Beomaster 2000 and 3000 series are prone to this where
the grease will even creep up onto the aluminum lid at its rear edge, collecting dust and dirt as it goes.

There should be no grease at the exposed parts of the hinges (or damper plates), only inside.
A little white spirit usually cleans it off.

Martin