1. grab the datasheet
PXA272x
2. locate the following signal pins:
- nTRST (Test Rest
- TDI (Test Data Input)
- TDO (Tet Data Output)
- TMS (Test Mode Select)
- TCK (Test Clock)
![pxa272x_ball_map](http://web132.s01.srv-net.de/wp-content/uploads/2008/07/pxa272x_ball_map.jpg)
4. find those on the circuit board
![pxa272x_socket](http://web132.s01.srv-net.de/wp-content/uploads/2008/07/pxa272x_socket.jpg)
5. heat your oven 🙂
![oven](http://web132.s01.srv-net.de/wp-content/uploads/2008/07/oven.jpg)
6. get the chip off the board
my first try wasn’t too successful
![pxa272_first_try](http://web132.s01.srv-net.de/wp-content/uploads/2008/07/pxa272_first_try.jpg)
so here we go again
![pxa272_removed](http://web132.s01.srv-net.de/wp-content/uploads/2008/07/pxa272_removed.jpg)
7. now trace the previously identified pins
8. mission accomplished:
![naked-magician-insane_jtag](http://web132.s01.srv-net.de/wp-content/uploads/2008/07/naked-magician-insane_jtag.jpg)
9. Resources
Wallaby JTAG, iPAQ 3600 JTAG
10. Notes
I think it is possible to do this without killing the device (which in my case didn’t matter because I got an already dead one just for this task).
Therefore you should prebake the circuit board at around 100°C for some time (to get the rid of the moisture) and only use the minimal temperature to unsolder the parts you want to remove/replace.
Also it might be a good idea to fixate the board so you dont accidentially move components once the solder is liquid (like I did – of course 🙂 ).
Don’t hesitate to contact me in case you need some more traces, or parts of this board (though I can’t guarantee nothing)