1 - Why do you not send the cards with the last update?. Customers will appreciate.
We do not unpack all packed-and-known-good units whenever there is an update.
2 - How in a 1200 in which everything works fine, and of course, all the video outputs, the only device that fails to work is the MK3, even with a re-solder of Lisa and all the steps to verify that the 1200 are OK?. Of course the MK3 doesn't works on my other 1200.
There's a number of possibilities for that - already discussed in this thread: Bad contact (not properly installed) and weak power supply are the most common causes.
In order to respect the European laws of guaranty, I chose to receive another new card,
Interesting interpretation of EU regulations. I choose not to go with that, and make this a revocation. Feel free to order again when the likely causes in your system are fixed.