Unfinished Projects

Jenn’s iPod has been on the fritz for a long time now, but the general problem with it was pretty well know. In fact, my iPod had the same problem too and it was explained and repaired for me by a friend who used to work at an Apple store. Basically, one of the connectors through which information travels between the hard disk and the processor is really flaky. My iPod was fixed just by unplugging the flexible printed circuit from this connector and then reseating it. I had tried this several times with Jenn’s iPod and it provided a temporary fix, but eventually came the time to try something a little more drastic.

The flaky connector is 40 connection, top contact type, surface mount flexible printed circuit (FPC) connector with 0.5 mm pitch. The particular one found in the iPod is some very low profile model that I don’t recognize (in terms of manufacturer or part number). However, we do use an electrically identical, but slightly larger, connector in my thesis experiment — HiRose FH12-A40-S-0.5SH.

So, the task is just to pop the old connector off and replace it with a new one I had lying around (which just barely fits). A photo of the insides of the iPod, minus the hard disk, is shown below.

The first step is just to get the damn thing open, which might be the hardest part. There are plenty of websites that give instructions, so I’ll just cover the basics. Holding the iPod face down, apply pressure to the back, along on of the edges, to push the metal back outwards and away from the white plastic front. This will open up a gap between the front and back pieces. Next you have to wedge something slender in there (or better yet, two somethings) and use them to detach the clips that hold it all together. I used jeweler’s screwdrivers but these will definitely ding up the plastic and bend the metal. If you want your iPod to stay looking pristine, you had better find a softer (plastic) tool.

Once it is open, the dominant feature is the hard disk, which can be unplugged. The FPC which connects so poorly to the iPod circuit board actually has a pretty nice connection to the hard disk, which seems to endure repeated connection and disconnection quite well. Following the FPC to its other end, you will find a crappy little connector soldered down to the circuit board. That connector has got to go!

I took the connector off with a little help from the soldering iron, but mostly just with a small screwdriver. This is not the right way to do it and I’m lucky that I didn’t lift off any solder pads. In fact, I’m really not the right person to look to for soldering advice, so good luck with this part. I will say that the connector in question is right next to the battery (which I didn’t try to remove), so you have to be careful about how much heat you apply.

The red box on the photo above shows the new connector that I put down. You can see how big it is compared to the 40 contact FPC connector of the type that Apple uses along the left edge of the circuit board (near the top). Hand soldering forty 0.5 mm pitch contacts is a pain the ass and I had to retouch several things. Fortunately, I had access to a microscope to check out my handy work. However, soldering under the microscope is not a skill that I possess, so the one time I tried that, I couldn’t keep track of where my hands were and I let the iron melt away as some of the plastic case (fortunately a part on the inside of the iPod). Anyway, I eventually made all the necessary connections and I am pleased to say that Jenn’s iPod is back to a fully functional state.