Error Manchester for Paradox Fob

So I’m trying to read and clone a Paradox Fob (C704 I believe by physical appearence, but my numbers on the back are “5021435” and “'APJN14”) but I keep getting an “Error Manchester at [number]” and all the data read from the fob keeps changing everytime I read it.

What’s wrong?

Using Proxmark3 Easy Generic 256kb
Want to clone to NExT chip implant




# If you want to use it, copy this file as Makefile.platform and adjust it to your needs
# Run 'make PLATFORM=' to get an exhaustive list of possible parameters for this file.

# If you want more than one PLATFORM_EXTRAS option, separate them by spaces:

# Uncomment the lines below in order to make a 256KB image
# and comment out the lines above


# To accelerate repetitive compilations:
# Install package "ccache" -> Debian/Ubuntu: /usr/lib/ccache, Fedora/CentOS/RHEL: /usr/lib64/ccache
# And uncomment the following line
#export PATH := /usr/lib64/ccache:/usr/lib/ccache:${PATH}

# To install with sudo:

we dont see those often here, normally the 512 version.

It looks like you have to deleted (uncommented) the correct files to compile the firmware correctly

I have a couple of thoughts, but not certain of either.

i wonder if the lack of memory is still the cause of the issue?

Can you read and write other tech without issues?

Other LF stuff?
or maybe try a build with HF and try Mifare Classic with a few blocks of data?

Yeahh I know, if I knew earlier it was a 256 I wouldn’t have gotten it xd

Yes I did successfully clone my condo key(T5577 if I remember well) to my chip.

Not sure to get what you mean by your last line?
I do know this Paradox fob is LF because the lf tune responds very well to the fob (-10v difference)
And what do you mean by try Mifare Classic with a few blocks of data? Writing the data to the fob? Reading a few blocks?

I can’t find a description of that Manchester error, nor see why or where it comes from. If I was able to I could debug that maybe?

Yeah, I wasn’t particularly clear.

I’m kinda thinking, your build looks fine, but I do wonder if the lack of free space is causing you the issue you are having.

Forget about your Manchester for now, I was wondering, if you were to do a new build, but rather that the LF build, try a HF build.
And try to copy and write a Mifare classic (if you have one)
If you get a similar error, It may indicate that space is your issue.
If it works, it may be an error with something specifically on the LF side.

I’m clutching at straws, but the elephant in the room is the 256…

So, I did try an HF build and I wrote on my chip my website URL. I didn’t try with a chip but I’m pretty confident the process would be the same and succeed.

So now what can we look into since the problem does seem to come from the LF side specifically…

I forgot to mention a really important thing
I was able in the past and even currently to read and clone LF chips with all this very same system.
After seeing this Manchester error, I tried to read another LF chip I have and this one reads without any problem.
I think all of this makes the problem even more of a mystery… :sweat_smile::joy:

Are you writing to another manchester or a T5577?

So, I have to be honest and say I don’t really get what’s Manchester. I think I found out it’s a protocol? And I was also not able to find out if this Paradox fob is Manchester protocol (but probably is because of the error).

Nevertheless, the other fob I read from was a basic T5577, yes.

ok, cool, can you try to write this to your T5577 fob.

lf em 410x clone --id 57002F17DE

Then check if THAT works

lf search will do

Alright, here it is:

So I get it that it works?

(Btw, I’m using the T5577 white card that was given as part of the DangerousThings Proxmark Easy kit (which I bought secondhand))

Thanks a lot for your time by the way :smiley:

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So we know that everything is working as it should.

So we just need to figure out why the Paradox is not working.

Can you try just an lf search with your paradox

I just saw @Iceman is online.

are you able to have a quick look at this issue.

The OP has a 256 version of the PM3 easy. :open_mouth:
But it appears to be working, as he just did a successful write of EM

but he is having a Manchester / Paradox issue
as per first post

Thanks in advance

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OP, with original card / fob on antenna.

lf paradox reader

post the output in text since its easier to test.

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Don’t have access to my computer atm, but if I remember well it just didn’t do anything at all, don’t find nothing.
However there was also an error that prevented me from launching “lf read” on its own (or within the lf search command, as I think lf search does incorporate lf read), saying something like “command unknown”.

Also, I was however before able to launch all these commands without any problem (but without testing with Paradox fobs)

That being said, I don’t think this “lf read, command unknown” error has anything to do with Paradox fobs because it also shows when I scan other fobs.

Hope I’m making sense lmao

You can see the result in my original post. Here’s the image again

Iceman is asking for it it TEXT, rather than a screenshot, so he can test it

Thank you for clarifying.

“lf read, command unknown” error

“Unknown command” is usually an strong indication that you have different firmware vs client …

pull latest/compile/flash/test

For support always be on latest source. Because fixed and potential new fix will be there…

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