’96 Twingo: remote control door lock defective

Hello together please for help my twingo bj96 is again kaput. and that the lock can not be taken away with the key. I gave a kolegen the twingo so he should look at it(without payment) he found nothing and for an investigation(miz payment) I simply did not have any money……I have to look in the google there is mentioned that in such problems the key or this decoder box kaput goes…….could it be the controller auhc?? and someone knows where you can get the best of it many times online or so it would then install/replace it itself……. And another question zuletz knows someone a car scrap site near Freiburg?? Maybe I could find something there? Please for help Greetings Muha