FauxFob chip mod!

I’m thinking about trying to swap some of the chips in my FauxFob, I have a spare PicoPass and a spare UG4 card I’m semi-willing to try melting down in acetone, and I think those 4 chips in one package would be a very fun little combo…

But before I commit to destroying a few cards, I believe I have to check whether the chips and the new antenna are compatible, right? Something like the capacitance has to match?

Is that something I can check with the PM3?

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The magic chips are about 25pF to 28pF capacitance… PicoPass chips appear to come in two flavors…

From this datasheet…

DS Picopass 2KS V1-0.pdf (657.1 KB)

So… it could possibly work but it won’t have great tuning… and with PicoPass chips it seems tuning is fairly critical whereas magic chips are very lenient when it comes to tuning.

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Thanks for the info!

Including the Gen4?

Well, I think I’ve decided to go ahead and try it, if the performance is too poor I’ll have to think about adding an antenna specifically for that chip…

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Spoiler alert, the PicoPass works pretty well!

Start of the actual project-y part


That was actually a lot easier than I was anticipating at every step, but I already made a whole topic, so here’s a guide-type-thing:

Gonna break this down into a few sort of chapters:

  1. Extracting the chip from the card
  2. Swapping chips on the board
  3. Converting chip B from LF to HF
  4. Results

Gimp file with some pictures and notes on it, if you want to do this yourself (Change file extension to .xcf):
Project.txt (13.2 MB)
Not really necessary though

Extracting the chips


Soak the donor card in acetone for a while, eventually it’ll start to wrinkle up and sort of dissolve in layers. I used some tweezers to pick the layers off

Eventually you should be able to see an outline of the chip, this was on layer 2 for me. I recommend using a flashlight to locate the chip prior to beginning the bath so you know where to keep an eye on before hand

Keep picking away at the layers over the chip, careful not to be too rough on the chip

Done!

Swapping the chips
Some simple soldering/desoldering


I like to solder one pad on components like this, and then remelt the solder and slide the chip in, then you can easily solder the other pad

2LF/2HF > 1LF/3HF
Chip B can be pretty easily converted from LF to HF


Cut the trace at purple, and make sure the two yellow have no continuity. Then just run a wire along green

I used a small drill bit to cut that trace

Make sure the wire is small enough to fit in the case. This was a little tighter than I intended

Results
I haven’t done any real measurements yet, maybe after I do this again with the UG4, but:
The Flipper reads the picopass super easy, and my HID MultiClass reader (with an MFGC on it) can get a read from ~1.5 inches eyeballed

Overall, I’m very happy with that for like an hour of tinkering

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Nice project :+1:

Funnily enough, This was my plan with the blue-bambino

I was going to replace 2 of the MF1Ks for a gen2 and a UG4.
I was going to keep the 3 LF in different modes, I didn’t consider converting to HF, that’s a great Idea, I would possibly add a NTAG216 and …hmmmmm, a couple of ideas for the last one.
ANYWAY
I got as far as opening it up, shit was tidy but also a potential easy fuck up, I allocated myself some time to do it, but it looked like it would take longer than I was willing to commit to.

I was hoping it was going to be as easy as a dual freq I have done before, and like your FauxFob ( I don’t have one, so thanks for opening it up and sharing)

My blue-bambino remains a project for another day, I will share when I do though.

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Got the Gen4 extracted and installed the same way, and it’s also working! My PM3 RDV4 can read it from maybe 3/4 of an inch?

Once again it’s good enough!

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Just random question. If an ic is the same size and shape can it be installed. Ive seen payment ics that size n shape in the walletmors.

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I mean… You could physically fit it in there… But the resonant tuning for the p60 chip in the walletmor is different from magic chips… it may still work just pretty terribly… maybe. More likely it won’t work at all though.

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Good to know that if it fits it doesnt always sits

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