Hello. I had a similar problem. namely, in the building where I have an apartment and I do not live there at the moment, the residents made a contribution for an intercom and a new door. and after some time, when I came to visit the flat, I look and the cage door is closed. I called some number and it was opened. I started to ask where is my key, where is my code and most importantly, where is my handset. I got the handset and in addition a bang. later I got a phone call from some neighbor who assumed it all. he gave it the code, I asked how to connect it and which of these six cables to connect. I got a hint with red under plus and blue under minus. so i did. I also had to set the sum of jumpers in the handset so that the number was 7. I combined and nothing, even I can not hear any signal in the handset. I was fed up and reported to this guy asking him to plug it all in. He gladly replied that he would do it, but he does not know when and I have been waiting for two months. Fortunately, I don't live there. And what is the subject, the building administrator is obliged to take care of everything and can not delete anything for it. good luck