HP 48G/GX darkened screen

[acoto]

Hello -

I have seen several HP 48G/GX with the center of the screen darkened. like this:



It seems to me that the liquid component diffuses over time on one of the glass plates.

It is curious that the corners do not seem affected.

Any way to fix it, but to replace the screen?

I am tempted to buy a damaged unit and start experimenting: heating, freezing... a dehumidifier.