Update: Today, I found two of the keys not working. Peeling back the white plastic showed that there was reddish junk in the dome switch contacts. I think I must have used slightly too much glue, and it flowed down with melted Rubylith. Or else the marker ink flowed down. I cleaned that up with acetone. But this is something to beware of. Moreover, some white light spills around the sides of the Rubylith.
My Treo 700P has keys that light up. One can
turn that off, but then it's a nuisance to type things in. So I ordered a piece of
Rubylith from ebay, about 8x11 in size. The lights come from little white LEDs on the same board that the dome switches are on. And I reddened the lights, as can be kind of seen in the photo.
Here's what I did. I
disassembled the Treo (not my first time). My initial thought was to just put a piece Rubylith over where all the lights were, but that would cover up the dome switches as well and that wouldn't be good. My next thought was just to use red marker over the white LEDs. But that isn't very effective. Finally, I cut strips of Rubylith about 1.5mm wide, and snipped them into lengths of about 5mm, and glued them over the LEDs. The photo on the right shows about half of them done.
I did the gluing with Super Glue (I like the cheap GTC brand [or off-brand] tubes they sell at HEB and Walmart, four for about a dollar). I held each Rubylith strip with tweezers, very carefully by the very tip, and put a very small amount of super glue on the strip, being careful not to get it on the tweezers. I then applied it to the LED, pressing it down with a toothpick, orienting it so it wouldn't get in the way of the dome switches. They didn't all stick as "super" as I hoped, perhaps because of the red marker, but eventually I got them all on.
I had to do two cleanup things. Two of the Rubylith pieces protruded close to a dome switch (bumps in the white plastic in the photos), and I snipped the ends with nail scissors. Also, I had accidentally dropped a Rubylith piece with glue on it, and so there was a glue spot on a dome switch. I was afraid this would harden, so I cleaned it up with acetone.
It all works. For some reason, the center of the five-way switch is not as clicky as it was, but it works. Also, the lights are a bit pinkish rather than deep red, but I am pretty happy. I rarely use a phone at a dark site, but sometimes I need to.
I was also going to make a screen overlay from the Rubylith, and I may still do that, but it blurs the image annoyingly, making small fonts hard to reed. I may eventually get a sheet of
Roscolux medium red gel filter
(I tried the small one in
my sampler pack, and while it perhaps isn't quite dark enough, and is more fragile than the Rubylith, it preserves sharpness much better).
