Handy Dandy Tips and Tricks Proxmark3 :pm3:


If you can’t use or modify your hf magic mifare Gen 2 chip or card (or in my case Magic Ring that I thought I’d killed) because you’ve written bad data to block zero (such as mis-typing data that doesn’t match the checksum) and you get a “BCC0 incorrect” error with “No known/supported 13.56 MHz tags found”, there’s hope! Using your Proxmark3, try this for a 4-byte UID:

hf 14a config --atqa force --bcc ignore --cl2 skip --rats skip

or this for a 7 byte UID:
hf 14a config --atqa force --bcc ignore --cl2 force --cl3 skip --rats skip

From there you should be able to do a hf search and see the device again without serious error.

I suggest that you then write a known good sequence to Block 0. If yours is a 1K chip with a 4-byte UID, an example would be::
hf mf wrbl --blk 0 -k FFFFFFFFFFFF -d 11223344440804006263646566676869 – force

From there you should have a readable 1K Gen2 ring, card, or chip and be able to write to it again.

There’s a good reference at THIS PAGE and it includes alternatives if you have a 4K chip and/or a 7-byte UID.