Kindle 4 hack: disassembly and serial I/O header

Kindle 4 hack and disassembly, including the mounting of a serial header

My brother is doing Kindle 4 hack, so he needed to open it up. He found only one video at iFixit.com from a guy who shows you how, but he used a lot of force. That’s not something you want to do on such a device, so he asked me if I knew a better way to open it up. I didn’t. But we did find the better way(I think).

What we’re gonna do:

  • Show all snaps and flaps that hold that back cover in place
  • Open the Kindle 4
  • Solder a header onto the serial I/O

My brother made a post about a USB to serial I/O device that he uses for his Kindle at his website.

Snaps and flaps

Let me first start by giving you a picture of the device AFTER opening it up, so you can see how everything is clicked together. First a plain pic, then a pic with all the snaps and flaps circled. Kindle 4 disassembled

First a little layout explanation. On the top, there is the connector. Below that, you see the motherboard with some radiation shields on top of it. On the left side of the motherboard, there are two cables. The small one is for the buttons on the side, the big one goes to the screen. On the right side, there is also a small cable that goes to the buttons on the side, and a somewhat larger cable which connects to the battery.

The battery is hidden behind an aluminum shield, which protects is from the upcomming prying.

Here’s a list with all the colors from the picture above, and what they are.

  • Yellow: This is a square of glue that sticks the shield on top of the battery to the rear of the case. More on this later.
  • Green: These are four plastic snaps that are clicked to the frame, around the battery.
  • Blue: Also two snaps that lock into two holes in the chassis.
  • Red: Again four snaps, this time a little weird-shaped. These are almost impossible to click loose, so while we tried that, we broke them. More on this later.
  • Orange: These are four plastic flaps, which stick underneath the edges of the chassis. Here is the key to why we used less force. Also more on this later.

Open the Kindle: The Sides

Start at the sides. It gets difficult immediately. Tools that might be usefull to get the cover off are:

  • Several small flathead screwdrivers
  • A spudger
  • Bank card, or other thin plastic objects
  • A pencil, matches, or other small things to keep the un-snaped snaps un-snaped.
  • A small fleshlight or, if you’re from the UK, torch.

The first things you encounter are the four weird-shaped plastic hooks. Here is a 3D model of how they are clicked.

If you want to take a close look(recommended!), here is a download to the .skp file. You can open it with Google Sketchup(which is free).

As you can see, you have to push the snaps a little backward to unlock them from the chassis. But because the rear cover sticks a little over  the edge, it is very difficult to get there with a screwdriver or spudger. We broke them off during the initial prying, but if you are carefull you might manage to get them loose with something like needles or a piece of spring steel.

As soon as one of them is loose, stick a match in there, to prevent it from snapping back.

In the red cirkle you see one of this, already broken, evil snaps. In the blue/green cirkle you see a more friendly snap, and right behind it one of the snaps that are around the battery.

Carefully work your way along one side, and when it is fully loose and secured with matches, go to the other side. Leave the top and bottom flaps alone! We’ll get to that later.

Open the Kindle: The Glue

The guy in the video I mentioned at the top of this post uses a heat gun to soften the glue, so that it is easier to pull the back off. We didn’t. If you have a heat gun you might try it, but what we did worked fine.

So, you have both sides loose and secured with matches and/or pencils. Now look into the Knidle with the flashlight, and locate the aluminum shield from the battery. It is glued to the rear cover. Start prying with a flathead screwdriver or spudger, whatever you want. Keep in mind the there are small electronics inside, so take it easy.

Here’s a pic of the glue. The Kindle is held open with a pencil.

Pry, pry, pry. Carefull. You just have to be patient and pry. You can reach the glue from both sides, so please do so. When the glue is loose, stick something in there to keep it that way. Note that you don’t need ALL the glue to be loose. If you focus on the side that is close to the mothearboard(so closer to the USB plug), you will get enough space to do the next step.

Open the Kindle: Rear cover

I’ll give you an illustration of what we’re gonna do. A sideview of the Kindle looks more or less like this(no, it doesn’t, but that’s just my drawing skills):

The orange circled flaps are shown on the very first picture of the post. There are four of them. Because they are so long, it would cost an immense amount of force to get them out. That’s what the dude on the video did. We thought that it would be nice to do it like this:

That is why you had to pry the back cover from the battery shield FIRST, because otherwise this wouldn’t be possible. So just start on one side, preferably the side close to the USB port, cause there is the most room. Stick something between one side of the chassis and the back cover so that it bends up(pencil?). Focus on one of the two flaps first. While pulling on the back cover, keep in mind that you don’t want it to go UP, but you want the flaps to go OUT of their sockets. So focus on rounding the back instead of forcing it up.

Here’s a pic of our first flap. Note that the pencil is actually on the wrong side. :-)

A little pullig later both flaps where loose:

So now there is plenty of space to pry the remaining glue off(if any).

When you’re done prying, you can just slide the remaining two flaps out of their sockets, and you’re done!

Now, whatever you want to do inside, first disconnect the battery. No excuses.

Solder a header onto the Serial I/O

The whole reason(for me and my brother) for opening this thing up, was to solder a header onto the on-board serial I/O port. It is a little hidden, but here it is:Kindle 4 serial header pinout

So basically all you have to do, is solder something onto that. That’s easier said than done, but it’s possible. We chose to use a little, sort-off standard female 3-pin connector. We didn’t want it to be to ugly, so we decided to file a gap out of the chassis and glue the connector in there. After a little filing and gluing it looked like this(on-board header circled in red):Kindle 4 serial connector

So, close it, and even though it is not as elegant as I hoped, it still IS a Kindle 4 with a serial port!Kindle 4 with serial I/O port

After some testing and stuff, the GND(red wire) turned out not to work. So we opened it up again. Here’s a good picture of what I meant earlier:

Inside we found that the GND contact was disconnected. We didn’t want to have the risk of that happening again, so we resoldered the GND pin to one of the radiation shields on the motherboard.

That was it! Serial I/O works like a charm. :-) A little information on how you can use the serial I/O can be found a my brothers website: http://pepijndevos.nl/2012/10/26/sparkfun-18v-usb-to-serial.html

If you want to know more, see more or you just want to tell that you really enjoyed this post, please leave a comment. :-)

Happy hacking!

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