Schlagwort-Archive: VPA compact

Baking a Magician to discover its JTAG pins

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)

4. find those on the circuit board

5. heat your oven 🙂

6. get the chip off the board

my first try wasn’t too successful

so here we go again

7. now trace the previously identified pins

8. mission accomplished:

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)