HELP! lF side of my NeXT

I may have gotten drunk and been playing with the LF side of my next. I vaguely remember

However. After trying to read it with the PM3. I get nothing. Lf search nothing

Even with both antennas ( proxlf and stock)
Checked orientation with field tester

Confirmed it’s reading with the t55 test card

Followed some advice to try and redo the config page

I don’t remember the exact command
But it was a write block 0. To the hex in the pic

However afterwards I noticed on the DT page that it’s configured as a em41xx? I believed it said.
Please help me. Lol
I don’t wanna cut this out just to replace it

Confirmed unresponsive with Xac V1 and 2

If you played around with it / programmed it, it would no longer be configured as a em41xx.

In terms of seeing if the chip is still physically coupling, try a lf tune and see if the voltage drops a bit when you couple it with your NExT

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That’s not gonna help: any old bit of metal or ferrite in the field will drop the voltage. It would only help if he had measured the voltage drop when it was working for comparison.

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That would be much better… but it will be a much larger drop in voltage if its a working implant.

In fact, I just tried my PM3 easy with my xSIID / xLED (so two coils / ferrite cores) and barely saw any drop. This would be due to no chip power draw, and also the HF coil / ferrite acting as a bandpass filter / amplifier. It’s probably still worth trying then :slight_smile:

(Saying that, I don’t have any LF implants for comparison, so I could be wrong, but I think that’d mean a super weak couple / low power draw from a LF implant for that to be the case)

Is there any chance you’d be able to give some baseline measurements? I don’t remember off the top of my head which implants you have though sorry

Well, as a counter-example to your little experiment, I shall point you to my craptastic Proxmark Theremin video:

In the video, the Theremin script does a “hf tune”, and I actually “play” it with my LF implant. The voltage drop is significant, even though it’s totally not the same frequency.

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That’s HF tune though… have you tried it the other way around by any chance?

I can do that, good idea. I don’t have a NExT though - only xEMs and a EM4305. Although one of my xEM is quite close to a M1k, so it would “emulate” a NExT well enough for that purpose I guess.

Not now though, I’m at work. I’ll do that this evening.

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Yeah, same thing really. It’s just that I only have a video of it doing hf tune.

I noticed that it just didn’t matter when I thought I’d add a switch to the code, to choose LF or HF: the code was buggy and selected the wrong tune command, but it worked equally well regardless of what I put in the field.

Ahh, pity about the NExT, but it sounds like a good idea with the xM1 though!

:+1: that’d be great!

On top of my head, I remember a drop under 1V with a well-placed LF transponder and a ProxLF antenna. But it’s been a while, I may be wrong. Seems about right though.

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No card stock antenna

With an LF t5577 card on it

Field tester so I know proper placement

Hand off - 70v
Hand on it —-69v

Now it fluctuates back and forth from 69-70 when I don’t touch it.

But it stays stuck as 697xxmv with my hand in position

Firmware for those that will want it
On windows 10

LF read from the t5577 card

But I don’t actually see a UID here

Not getting any actual data from the test card it looks like

What’s the exact difference between no hand on PM3 and best positioned hand on PM3?

If you get less than 500mV, I’d say it’s toast.

I’ll try my xEM at home. Leaving work now. I should be there in 45 minutes - or 3 hours, depending on how stuck I get with my bike in the freaking snow storm :slight_smile: