Renault megane 53 plate, card not detected and won't start?

Hi, I have recently bought a second hand renault megan on a 53 plate. There were a few faults already on the car when I bought it, Driver window doesn't work, started to rev high when driving it and the key card wouldn't lock the doors?? But now since the key card was opened up to c if any of the wires needed soldering to get the key card to lock the doors (all wires were attached to the board so nothing needed soldering?) Everytime I put the key card in the reader and press start it comes up on the dash 'card not detected'?? I have read every forum and watched every kind of video on renault megane and how to fix this problem but NONE of them have worked! I have tried the knife method and I have taken the front of the dash off and taken the reader out and tried the key card in it then but still saying the same thing 'card not detected' and there is nothing that I can c needs soldering inside it and I put a brand new battery in it and still nothing!!?? Please can anybody help me with this problem???