Nokia 5110 irregular display

I have two 5110s. One is fine but the one that is actually in service is far from satisfactory. It works fine for a while, it can be for over a day, and then the display will disappear. Just now I have caught it for the first time where the screen has gone black, as if it was out in the sun. It is 1 AM here.

I surely can't have a heating problem. The ambient here in the office is 26, the device is running off 3.3v, and the blue background light is so useless it is permanently disconnected. It is soldered directly onto a proto shield with about 1mm clearance, but I can't imagine ventilation to be an issue.

Is this sort of thing common with these devices?

Think about where / how those displays were intended to be used and ask if they behaved the way they did, would you have heard about them?

I have used no less than 20 of similar devices (for 7110) and I have nothing but praises for those devices.

would you have heard about them?

Very likely, and quite possibly as a text on my 5110 phone. But I recall reading that these items were “surplus”, hence the question.


My understanding is that they are "re-manufactured": taken and reconditioned from used phones.