Flat panel display rot - "tunnel vision" in electroluminescent and other displays- bad seals.

Brent Hilpert hilpert at cs.ubc.ca
Wed Jul 20 17:32:03 CDT 2016

On 2016-Jul-20, at 12:52 PM, Ian Finder wrote:

> I have a few GRiD compass systems and some are suffering from massively
> decreased contrast on the edges of the displays:
> [See the system on the left]
> https://www.instagram.com/p/BIGGzUzgat-/?taken-by=tr1nitr0n
> [Or this one:]
> http://www.ripstick.com/USCM/images/Grid_Compass_1101_Laptop_in_Box_002.jpg
> Meanwhile, other EL systems I have- like my HP integral PC- haven't
> succumbed to this.
> I have seen similar issues on amLCD displays in my Tadpole, Toshiba and
> other machines, so this is something we all may have to confront.
> -------
> I was wondering if the folks here had theories?
> I'm thinking moisture (or air) might be leaking in from the edges of the
> glass panes, perhaps from a compromised seal- sorry for the silly picture
> but you can see the composition of the display here:
> https://www.instagram.com/p/6BXaLBtSzd/?taken-by=tr1nitr0n
> Does anyone know how one might prevent this from progressing- storage tips?
> Could it be reversed?
> Better yet, does anyone have ideas on how to rapidly dehydrate the display?
> Perhaps there is even a way to re-seal them.
> I think all two-glass-pane displays that don't have a vacuum may eventually
> succumb to this.
> Perhaps it is just oxidation and not moisture, but I'd love to hear any
> theories.

Are you convinced this is a panel problem rather than a driver electronics problem?

In one picture it looks like the sort of thing that happens when you have to turn up the brightness (for some types of display), resulting in partial illumination in other areas of the screen.

I've never had opportunity to repair or work on EL flat-panel displays, I'm not familiar with the driving techniques and requirements, so this is just a query/guess. (I see it's an X/Y matrix drive scheme, but the voltages & timing & phasing I don't know about.)

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