And now to something completely different ... when discussing the keyboard illumination of the N900 with Joerg, I commented that it left a lot to be desired. He found that remark interesting. As it turns out, I have one of the N900s with the "dark keyboard syndrome".

Since we plan to keep the illumination system of Neo900 similar to N900, I had a look at what may cause this. First, with the keyboard fully assembled:
https://neo900.org/stuff/werner/klig...bad-closed.jpg

For comparison, a healthy N900 looks like this:
https://neo900.org/stuff/werner/klig...ood-closed.jpg

I then removed keyboard frame and key mat, to reveal this unhappy sight:
https://neo900.org/stuff/werner/klig...d-open-top.jpg

Comparison with the good one:
https://neo900.org/stuff/werner/klig...d-open-top.jpg
https://neo900.org/stuff/werner/klig...h-open-top.jpg

Seen from an angle:
https://neo900.org/stuff/werner/klig...open-angle.jpg
https://neo900.org/stuff/werner/klig...open-angle.jpg
https://neo900.org/stuff/werner/klig...open-angle.jpg

Note that the light the LEDs leak onto the light spreader of the "bad" device seems brighter on the photo than it looks to the naked eye.

I tried to see if anything had come loose, but I couldn't feel any movement when applying pressure around the LEDs, and the light distribution didn't change.

So far, so bad. Other than diagnosing that this light spreader doesn't, I couldn't find much else. The cause for the sorry state of the light spreader is also unclear. Some possibilities:
- degradation of the plastic of the light spreader,
- undesirable chemical reaction between light spreader and adjacent adhesive,
- unusual environmental effects (maybe the light spreader just doesn't like the climate in Buenos Aires),
- some history of abuse (I got that N900 second hand and don't know what may have been done to it in the past),
etc.

Or maybe it was argentobacter plastivorus rex Of course, then it may have infected Joerg's phone while at the camp, then his entire stash at home, ... I guess nobody expected the zombie apocalypse to start quite that way.

Differences in "normal" degradation could also come from Nokia changing the chemistry between production runs. Of course, we wouldn't be able to tell. It could also be the result of a repair using a non-original light spreader, but I'd consider this unlikely.

Any ideas ? The problem seems to be rare in general, but if there's some precaution we could take to make Neo900 less likely to suffer such a fate, we'd of course like to do that.

- Werner