Hacking a Sony ICFCD3IP to change Time Format

I recently wanted to upgrade my bedside alarm clock to one that had both an audio input and an iPod charging capability. I also wanted something small but with a large time readout and 2 alarms. I also wanted something that showed a 24-hour time format (instead of the 12-hour AM/PM format). The Sony ICFCD3IP (and it's less expensive brother the ICFC7IP) met all my requirements - EXCEPT that the ones sold in Australia were hard-wired to only show 12-hour time format. The same exact model of radio sold in continental Europe (though not the UK) has a 24-hour format. Searching Google didn't reveal anything so I went and bought an Australian model at a local electronics store with the intention to modify it. Long-story-short, after trying every possible "undocumented" button combination, I was hoping to find a "jumper" or something inside that would let me change the configuration. Instead I found a serial port (JTAG or other) which is obviously where the factory sets the localisation config into the device. At this point I gave up.

But for any of you out there who wish to hack / modify / convert one of these radios, you will need to work out the protocol used to update the config. The easiest way to open the device without leaving any trace is to start with the door (remove all the Phillips screws on the door and carefully disconnect the ribbon cable) then unscrew all the screws around the CD Player part to remove the cover and reach the serial port which is roughly behind the backup battery compartment. Removing the base then needs a further two screws behind the main circuit board and then several screws on the base followed by careful prying since the two pieces are also glued together. The base mostly holds the speakers, dock mechanism and radio circuitry.

EPILOGUE: As I was on a mission to get a 24-hour version of this product, I persisted beyond what a reasonable person might do. Via Amazon.fr I found a place in Germany (AVIDES) that would ship one overseas. Amazon.fr wouldn't ship the product outside of Europe, but AVIDES was selling ex-demonstrators and would ship to Australia. Coincidentally, since the AU$ happens to be very strong at the moment, the total price including shipping was actually less than buying it locally! Having received the device in perfect order (you can't even tell it's a "used" one) I am very happy with it. The European model has an automatic daylight savings mode (which can be disabled) that will not work in Australia because of the opposite seasons. Other than that, it's exactly what I wanted. As a bonus, the European version also has an expanded AM radio range.