I have an HP-11C that several months ago started developing a problem with the display.
The lower right corner of the display has turned black.
It is black regardless of whether the calculator is on or off.
I tried new batteries, same thing, black with or without batteries.
The black area is roughly triangular, with side of about 5-6 mm.
The blackness has spread along the bottom of the display, reaching 1-2 mm in some areas.
Is this anything that a slightly klutzy SW Engineer could repair?