HP48G screen mark

[Phenixg]

Hello Guys,

Do any of you know why my HP48GX screen suddenly developed that white oval mark. The mark was not there 2 months ago when I last used the device. It was stored in its pouch on top a speaker.
We live in Florida where humidity is often a problem but this is not so much a problem in my place. Do you know if it is irreversible?
See attached pictures.

[TomC]

Very bizaare, but given its elliptical 'regularity', I suspect it is a long term response to the magnetic field of the loudspeaker??? I don't believe the response of LCD displays to magnetic fields is well documented...

TomC

(02-25-2021 05:31 PM)Phenixg Wrote:  Hello Guys,

Do any of you know why my HP48GX screen suddenly developed that white oval mark. The mark was not there 2 months ago when I last used the device. It was stored in its pouch on top a speaker.
We live in Florida where humidity is often a problem but this is not so much a problem in my place. Do you know if it is irreversible?
See attached pictures.

[Maximilian Hohmann]

Hello!

To me this looks like a crack in the protective plastic in front of the display. As if something heavy was put on the calculator at some time or someone really pressed hard on the screen. If it still works that is just a cosmetic issue.

Regards
Max

[Phenixg]

Looking at it with a magnifier, the mark seems to be limited to the external layer(possibly a/the polarizer). it definitely looks like a burn mark (or a bobble). I can confirm that did not happen with direct contact to anything radiating heat, leaking chemicals or something heavy.

[Ren]

Crop circle?
B^)