HP-48's display with an unusual(?) stain

[cruff]

(09-25-2023 10:10 AM)vaklaff Wrote:  Oh well. Thanks for the assessment. By the way, what's exactly happening there, does it have a name?

"LCD rot" is one term used to describe it. It is caused by delamination or other breakdown of the panel's structure, possibly caused by extreme temperature, humidity or physical stresses. Once started it tends to get progressively worse. I had this happen on two navigation displays on my Goldwing, I could track the progress of the failure as more pixels started dying. You can imagine an automotive display has to withstand even harsher conditions than a calculator!