Potentiometer under Label

[Sergio Nayar]

Today I took my Jornada 568 appart (it's way out of warranty anyway) to fix a problem with my digitizer and in the process I found the potentiometer. It even can be reached from the outside by peeling the label under the battery compartment (see pic)

I wonder what is it for... Any clues?

By the way... I was able to fix the digitizer problem, it was not aligning properly

Thanks,
Sergio

[IronGuy]

I've been having some problems with my 568 digitizer. There's an area about one third the size of a quarter on the bottom center of the screen that won't align properly. Some buttons on the bottom of programs are impossible to tap. What did you do to fix your problem?

I have no idea what that potentiometer is for.

[Sergio Nayar]

--- DISCLAIMER: I DID THIS PROCEDURE KNOWING THAT I COULD POTENTIALLY DAMAGE MY POCKET PC, IF YOU ARE STILL UNDER WARRANTY YOU WILL VOID IT. IF YOU TRY THIS AND DAMAGE YOUR POCKET PC IT'S YOUR OWN FAULT! :P ---

Well, here's the story:

I was totally upset and almost trashed my Jornada because of this digitizer problem, it was driving me nuts!!!, besides I consider that I didn't had anything to loose since it was useless to me as it was.

At first I thought it was the same unfixable digitizer problem that plagued the first batch of iPAQ 3630's but this time I decided to "examine" the Jornada 568 innards, so I took it apart.

First I did a full backup. Then I removed the main and backup batteries (important to remove the backup battery so you won't short something in the process). Then I removed all the screws and casing from the back, at this point with all the screws removed I noticed that the faceplate could also be removed and the screen was completely uncovered (Don't try to reach the screen from the back of the J568!) , at that point I decided to seat the Jornada on the battery (be very careful here because since you don't have the case to align the battery in the contacts you could potentially damage your J568!) and it turned on. Then I got to the point where the OS let's you align the screen and just couldn't align it properly as before, but then I pressed my finger LIGHTLY on the portion where what appears to be the digitizer ribbon that goes to the back of the main board (bottom right of the screen) and tried the alignment again and this time IT WORKED! I didn't have to press that portion of the digitizer anymore, but I decided to put some tape over that portion just to make sure. Then I put everything back together and the digitizer is working great again!

Let's see how long it stays that way!

I will post some pictures of the procedure sometime tomorrow...

Best Regards,
Sergio Nayar

[MatthewF01]

i just might be able to offer some insight onto the possible functionality of that pot....


I remember back to when the Game Boy Advance (Generation 1) was released. Some people removed the back label, or punched through it, to find a hole with a small pot underneath. Many people f-ed around with the pot, and realized it controlled the 'brightness' of the LCD screen.

There were a few games that many people said looked just too damn dark (Castlevania was the worst). They said that adjusting the pot made it much more visible.
The reason the batch of release games looked different (more dark) than the ones that came out a bit after, is because the reference systems probably had their screen brightnesses set at a different level, so the game was developed with a certain brightness in mind, but by the time the GBA hit market Nintendo changed the pot setting i suppose...

the effect of the pot was that the screen looked more washed out, and sometimes got the wavy 'refresh' lines that you could see pretty clearly... a few other problems too like you could just totally crap out the LCD...



in other words, i wouldnt touch it. Its probably something for the LCD.



not bad for a 17-year old....

[Sergio Nayar]

--- DISCLAIMER: I DID THIS PROCEDURE KNOWING THAT I COULD POTENTIALLY DAMAGE MY POCKET PC, IF YOU ARE STILL UNDER WARRANTY YOU WILL VOID IT. IF YOU TRY THIS AND DAMAGE YOUR POCKET PC IT'S YOUR OWN FAULT! :P ---

First remove the screws (you'll need a small torx wrench and a small phillips driver)

[Sergio Nayar]

--- DISCLAIMER: I DID THIS PROCEDURE KNOWING THAT I COULD POTENTIALLY DAMAGE MY POCKET PC, IF YOU ARE STILL UNDER WARRANTY YOU WILL VOID IT. IF YOU TRY THIS AND DAMAGE YOUR POCKET PC IT'S YOUR OWN FAULT! :P ---

Then remove the back casing and proceed to remove the rest of the screws (one torx and two small phillips).

[Sergio Nayar]

--- DISCLAIMER: I DID THIS PROCEDURE KNOWING THAT I COULD POTENTIALLY DAMAGE MY POCKET PC, IF YOU ARE STILL UNDER WARRANTY YOU WILL VOID IT. IF YOU TRY THIS AND DAMAGE YOUR POCKET PC IT'S YOUR OWN FAULT! :P ---

Now remove the rubber sides from the Pocket PC...

[Sergio Nayar]

--- DISCLAIMER: I DID THIS PROCEDURE KNOWING THAT I COULD POTENTIALLY DAMAGE MY POCKET PC, IF YOU ARE STILL UNDER WARRANTY YOU WILL VOID IT. IF YOU TRY THIS AND DAMAGE YOUR POCKET PC IT'S YOUR OWN FAULT! :P ---

This part is a little tricky and need to be very careful not to use excessive force. With your nail or a thin object like an Exacto Knife carefully lift the beezel from the locks (one on each side)...

[Sergio Nayar]

--- DISCLAIMER: I DID THIS PROCEDURE KNOWING THAT I COULD POTENTIALLY DAMAGE MY POCKET PC, IF YOU ARE STILL UNDER WARRANTY YOU WILL VOID IT. IF YOU TRY THIS AND DAMAGE YOUR POCKET PC IT'S YOUR OWN FAULT! :P ---

Now you can remove the faceplate and reveal the screen!

The arrow indicates what appears to be the digitizer ribbon, here's where my problem was...

[Sergio Nayar]

--- DISCLAIMER: I DID THIS PROCEDURE KNOWING THAT I COULD POTENTIALLY DAMAGE MY POCKET PC, IF YOU ARE STILL UNDER WARRANTY YOU WILL VOID IT. IF YOU TRY THIS AND DAMAGE YOUR POCKET PC IT'S YOUR OWN FAULT! :P ---

Now we are going to connect the battery to the Pocket PC but first to be safe, replace the back casing and put the marked screw back to secure it and to make the contacts more steady...