Well, time to update. I ordered the Teensy in a strange website which did not inspire me a lot of confidence, but it was in Germany, cheap and with free shipping, so I played the cheapman role again and I ordered it.
It took two days to arrive. I came with no box. Just a plastic envelope and a Teensy paper that explains the pins... I did not know if I got a counterfeit board or a counterfeit of a counterfeit. What I knew is the pirate version came with a nice box and this came with nothing.
I inspected it, connected it to the open panzer software and flashed the newest firmware with no problems at all. But I can do that in my damaged board too, so it did not say a lot.
Then I grabbed some pins and I did a dry fit... It did not work and I started sweating... If I solder the pins, I lose the guarantee and I cannot return it in case of a counterfeit... I tried several things more and well, I had to pull the plunge and to solder the pins on it.
Fairly easy job that I did with very afraid of messing it, droping a solder iron blob over the microprocessor or things like that... Surprisingly it went smooth and nice.
I started the tank, and no sound. I flashed the soundcard firmware again, and no dice. I connected the TCB and I got a promp saying I had to update it. I did it, and after that nothing worked. I paniked and I thought I damaged something, so I tried installing and uninstalling things until I realized all I had to do is to flash my own config in the board again, lol.
Ok, the tank was working again, but still no sound. I tried everything and I cursed myself for not ordering the teensy board with the pins already soldered for 2 extra euros. The cheapman's curse, for ordering in strange sites and saving pennies ordering with no pins, lol. I also thought the other part of the OP soundcard was damaged.
I read the wiki, I flashed and unflashed everything again, and then... Well, it embarrases me, but it might make you laugh. Then I saw it. The speaker. It was just not plugged in.
For God's sake, how could I have missed that? It brought me to desperation, pretty much like when I could not shoot the cannon because of the repair switch, lol.
But yeah, the thing is the board works, I have sound and everything is as expected. I liked more the purple color in the soundcard, but now I have a story to tell.
Pfew!