I recently bought a Palm M100 listed as “For Parts” that wouldn’t turn on, and that had a pretty big portion of the screen darkened.
I fixed the “Not turning on” part pretty easily, I’ll cover that in another post, but the issue with the screen was not so trivial. So, let’s dive in on how I managed to tackle this situation. As can be seen, that darkened portion really affects the usage.
Understanding the issue
A lot of those grayscale screens tend to develop this exact issue, not being limited to Palm devices. This happens due to degradation of the polarizer and/or the glue that adheres to the LCD. So, in the cases where the polarizer film can be accessible and be replaced, this issue can normally be resolved by doing so, and as you guessed, that’s the case with the device focused in this post.
A word of caution
This procedure can cause irreparable damage to your device, yourself and your cat. Proceed by your own risk and do this outside. Do not do anything you don’t feel comfortable doing, and always treat your cat (and other pets) right.
So, we need to gain access to the screen, start by removing the battery, stylus, the front plate, and then all the Torx T5 screws from the back. Carefully pry open the device. There is nothing attached/glued to the back housing of this PDA, so it comes of cleanily. After that, remove all the three ribbons connecting the screen to the mainboard, as shown on the upper part of the picture below. All the locks are delatched by pushing the ribbon-facing side up. After removing all ribbons from the mainboard, simply press against the screen and it should pop off the frame, as it is only glued to it. The three ribbon connectors and cables. All connectors are delatched in this picture.
Analyzing the situation
Ok, now that we’ve managed to get our hands on the screen, let’s detach the digitizer from the LCD. Probably there’s a better way of doing this, but I’ve just started carefully poking a pick between the parts, and twisting it until it all detached from one another. The ends of the digitized are very sensible, so be gentle. Mind the ribbon for it too. Trying to detach the digitizer from the LCD.
Eventually it all came apart: Digitizer and LCD detached.
Ok, now just take a look at this screen. Yikes. LCD Closeup. Yep, it’s bad.
Let’s get to work
Just remember, our goal here is to remove the polarizer film, and said film is normally the first (or last?) layer of the materials that compose a LCD panel, so it should be a matter of just peeling it off. By looking close at this edge, it seems that we may have a nice and easy entry-point to start the peeling.
Again: Do this outside in a well ventilated area. The smell of the adhesive is very strong. Look right in the corner, the film already appears to be peeling off.
And I started to peel right in that spot, and it seems to be going good. Ughhhh that smell…
The plot twist
I continued to peel it off, and when I reached the center of the screen I realized something that got me confused: The dark area was on the screen, and not on the film as expected! Oooof… See the dark area on the panel itself?
I checked the polarizer film against a white surface, and sure enough, no markings there. Is the LCD just bad then? No dark area on the polarizer film
Well, that’s unexpected! So I hopped on the Discord Server of Palm DB and asked the Pro’s, and they told me: That’s the glue! Just remove it!
And so I did it. To test the theory, I’ve removed two small circles of the glue using a plastic tool: Two spots of glue removed
And behold! It worked!!! When I positioned the polarizer film I just removed on the top of it, the darkened area was clearly gone on those two spots! See? It’s not dark anymore!
Let’s get to work again!
So, let’s get rid of this pesky glue. I got my plastic tool, and start dry-scraping it, and oh boy, DO NOT DO THIS. That powder is not… Cannot… Be healthy. Again: Do not do this.
Just to check if it was working: Yes! It’s working!
After getting a little nauseated by the glue’s smell and powder, I had the brilliant idea of soaking it in Isopropyl alcohol and OH BOY, now we’re going places! I used a old credit card as spudger and scraped the hell of that thing using a lot of force, because even using the alcohol to dissolve it, the glue was not giving up: Looking much better now, right?
After a lot (really, a lot) of scraping I had come to the conclusion that this screen was DEAD by the pressure I’ve scraped OR it was free from the glue.
As usual, I’ve put the polarizer film on the top of the screen to check the progress, and was looking much better now: No more dark area!
I assembled the PDA just enough to power it on and test the screen to check if I’ve killed it, and for those who are a little familiar with those devices, should be pleased to recognize that screen! As seen, I’ve just jammed the polarizer film on the top of the digitizer. Who knows this screen?
That’s great! As the polarizer film per-se was still good (although missing the adhesive) I thought of just scraping the glue off too and just re-use it. The M100 is already in very rough condition and I don’t plan on using it anyway, so yeah, I gave it a try, and it turned out better-than-expected actually! After cleaning most of it…
After more clean up, I’ve positioned the polarizer between the digitizer and the LCD, and close it all up, and it didn’t ending up looking too bad actually: Right? Not that bad…
For a total of 0 moneys spent, I call this repair a success! If you have some PDA with this issue, and have the tools, the time and you’re feeling adventurous, give this procedure a go! Worked pretty well in my case.