HP 48G screen is kind of cracked

[dfberquo]

Dears, has anyone seen this type of defect on the LCD of the HP48g calculator? The LCD is not burnt out. Its screen is kind of cracked. I'm thinking about using sandpaper to try to fix this problem. Does anyone have any suggestions? Thanks.

[franz.b]

I think the polarizing film is degraded. I suppose you can take it off like a sticker. I wouldn't use sandpaper. Then it must be replaced with a new generic.
I hope someone more experienced confirms or disproves my hypothesis.

[BruceH]

That's very unusual - never seen anything like that before. It looks like whatever it is is on the screen's surface so two possibilities come to mind.

One is that a previous owner attached a screen protector (perhaps by trimming down a mobile phone one) and that has now 'gone bad', in which case you might try to see if an edge can be peeled up.

Otherwise something may have been spilt on the screen - but given how clean the rest of the machine looks around and under the bezel, that seems unlikely. Maybe start by gently rubbing with one of those spectacles cleaning wipes?

I certainly wouldn't use sandpaper - if only because you will inevitably scratch the bezel. And if you do use anything liquid, remember to hold the calc upside down so an inadvertent spill runs down your hand rather than into the calc.

[CMarangon]

(11-11-2021 10:50 AM)dfberquo Wrote:  Dears, has anyone seen this type of defect on the LCD of the HP48g calculator? The LCD is not burnt out. Its screen is kind of cracked. I'm thinking about using sandpaper to try to fix this problem. Does anyone have any suggestions? Thanks.

I never saw it before in calculators, but I've seen a similar issue on pc monitors.

It seems that it is a problem due of heat.
Did you leave it under the sun light/heat?

[GreyUser]

The top layer, the polarizer has melted - typically from having been left in the sun, usually on the dashboard of a car.

A new screen can be found in any 38/39/48/49 series machine, it’s a relatively easy swap once you learn how to open the unit.

[dfberquo]

This phenomenon on the LCD screen is very strange.
I didn't leave the calculator in the sun. It was permanently protected in the drawer. I will try to remove this film. Apart from this problem, the LCD does not look burnt.