Self-healing Fluke 8010A LCD display?

[golden_labels]

Some time ago I got a Fluke 8010A. The unit was perfect except for the LCD, which experienced the well known bleeding issue:


(cropped from bd139’s photo from here)

Yesterday I finally got energy to replace the LCD. To my surprise… nothing has to be replaced. The LCD fixed itself.

Any comments? I did nothing to it. I didn’t apply preasure, I didn’t treat it with heat or cold, it was in normal room conditions all the time. Just sitting unused for a few months. Immediately after buying the unit I disassembled it for cleaning and to see how to approach LCD replacement. But after assembling it back everything the LCD still had the same issue even a week later, so I doubt it had any effect.

[helius]

There appears to be a gap between the common knowledge of how LCDs work and the technical specifics, leading to informal terms like "bleed" being used for specific situations in the absence of a physio-chemical analysis. But working ab initio from the basics, we find that liquid crystals are long polymer chains with both positive and negative charges (zwitterionic). That property is what makes them twist when an electric field is applied to the indium-tin-oxide coated glass plates. The positive and negative charges create a risk of solidification, as I outlined in another thread.

It may be that simply being stored in a particular environment (temperature and humidity, plus importantly any ions present in the air) has given the liquid crystals the potential to free themselves from the cross-bonding that was preventing their proper orientation.

[golden_labels]

I may be missing something, but wouldn’t solidifcation lead to a persistant image/artifacts? Not to the effect visible in the photo?

I’m not sure, if that’s clear, but in his situation the segments work and correctly change state. They just bleed outside of their intended boundaries. Phase change happens as it should, but also away from electrodes.

[helius]

If there are no persistent artifacts then it may be a different cause. One idea is that a greater region of the liquid crystal may change shape due to enhanced phonon activity. I'm not sure how to reconcile that with the healing you observed (and which environmental factors could be responsible).