Proxmark3 community

fergusfp

Contributor

Registered: 2019-03-24

Posts: 2

Issue Un-bricking Proxmark3 easy with J-Link mini EDU

Good Afternoon
My name is Fergus and could do with a little help with my bricked Proxmark3 Easy. I am a lecturer for a design school, I teach into an interaction design course. Last year there was allot of interest in RFID, so I got a proxmark to help me deliver a workshop designing an interactive table. We used the Proxmark to program some magic cards... etc.

It was exceptionally slow so I tried to upgrade the it to lasted iceman fork. However I must of done something wrong and this process didn't complete resulting in a bricked proxmark. It was no longer recognised by Mac nor Windows and I couldn't program it again even with the button pressed in on power up.

Fast forward to a last  week. The students went on spring break and a few of them requested to do work with RFID when they return in a couple of weeks for their third term projects. So I ordered a J-Link Mini Edu, and downloaded the latest iceman fork and J-flasher V6.5a, it arrived a couple of days ago and I hooked up the SWD cable to a breakout board and from there hooked all the wires across to a header I soldered onto the proxmark for J-Tag programming.

However I get this message:

Connecting ...
- Connecting via USB to J-Link device 0
- J-Link firmware: J-Link EDU Mini V1 compiled Mar  7 2019 15:20:28
- Device "AT91SAM7S256" selected.
- TotalIRLen = 4, IRPrint = 0x01
- JTAG chain detection found 1 devices:
-  #0 Id: 0x3F0F0F0F, IRLen: 04, ARM7TDMI Core
- Auto JTAG speed: 2667 kHz
- Target interface speed: 2667 kHz (Auto)
- VTarget = 3.299V
- TotalIRLen = 4, IRPrint = 0x01
- JTAG chain detection found 1 devices:
-  #0 Id: 0x3F0F0F0F, IRLen: 04, ARM7TDMI Core
- Executing init sequence ...
    - Initialized successfully
- Auto JTAG speed: 2667 kHz
- Target interface speed: 2667 kHz (Auto)
- ERROR: Memory access timed out @ 00200000 -> JTAG speed too high ?
Failed to halt CPU for clock frequency detection!
- ERROR: Failed to measure CPU clock frequency
- ERROR: Failed to connect.
Could not determine CPU clock frequency.

I can see it is a 16MHz crystal however even if I enter is manually I get the same results.
Same if I manually set the JTAG speed to 200MHz instead of auto.

Any help would be most appreciated.

Thank you

iceman

Administrator

Registered: 2013-04-25

Posts: 9,506

Website

Re: Issue Un-bricking Proxmark3 easy with J-Link mini EDU

Some nice entries in the proxmark wiki regarding de bricking over jtag.

https://github.com/Proxmark/proxmark3/w … -buspirate
https://github.com/Proxmark/proxmark3/w … ing-Segger

Not to mention all posts about jtaging a pm3 here on the forum. Have you tried searching for 'jtag' ?

grauerfuchs

Contributor

Registered: 2018-08-28

Posts: 50

Re: Issue Un-bricking Proxmark3 easy with J-Link mini EDU

You might also want to consider the article http://www.proxmark.org/forum/viewtopic … 890#p33890
It looks like the PM3 Easy is frequently coming with JTAG locked out, and flashing from what's previously installed seems to have issues at first for many people. The last few posts in that thread have a quick and easy method of wiping the chip and re-enabling JTAG.