Cloned card won't open gym door


So this is the second time I’ve cloned anything to my NExT. The first one, I cloned my door badge while I was on a work trip and it worked beautifully.

I have just moved into a new apartment complex, and lo and behold they use HID cards for the fitness room. I fired up my Proxmark 3 Easy, read the card and cloned it onto a test card as well as my NExT. Double checked that all the values are the same, then walked over to test it out. To my surprise, neither the test card or my implant succeeded in opening the door, but the card they gave us did. I came back and re-checked that all the data is exactly the same and it is.

So, what gives? Anyone know why the cloned card and NExT don’t work but the legit card does?

Try using the RFID Diagonstic card that was included with your next on that reader.

I’m having issues with the readers at one of the buildings I work at not letting me into any door, because I’m only getting a HF 13.56MHz signal from those doors.


Turns out it is just a really finnicky door system, and both the test card and my NExT actually do work.


Thank you though @timwat1 ! That was a solid idea.