Hi,

I bricked the router trying to restore the original image (http://wiki.openwrt.org/toh/actiontec/mi424wr).

I need help/pointers on how to unbrick the router.

I guess the only recourse may be to restore the firmware via JTAG.

Is the J20 block the JTAG header? Any recommendation on which JTAG cable to get?

Thank you.

you could connect to serial port and try to enter the boot loader. thats how we normally debrick routers like the tl-wr1043nd.

I (think I) managed to reflash the router but it is still bricked.

Here is what I did:

Got a Universal JTAG Adapter

Wire it up in buffered mode (there is no DINT pin)

The 20 pin JTAG header on the router is (I think) like this:

tjtag v3.0.2-RC2 (unsucessful)

tjtag recognises the cpu but not the flash.
According to dd-wrt wiki, the flash chip is a Numonyx JS28F640J3D-75.
So I tried forcing it with /fc:71 which is Intel 28F640J3 4Mx16 (8MB) but no go, can't read (all 0x2) or write (hang).

h-jtag v1.1

Load the following IXP425-28F640J3.hfc into H-Flasher:

I flashed the router with an 8M image which I have dumped previously using jungo-image.py, still bricked.
I also tried rb-mi424wr-ROM.bin, also still bricked.

"Still bricked" means I can't ping/telnet 192.168.1.1 (Port 1 for the original image, and WAN port for the RedBoot image)

The flash was verified to be the same as the original file by H-Flasher.

A ttl-232r3v3 is on it's way...

SUCCESS!

Use the H-Converter to swap the endiness of the image.bin file, flash, and the router is now back in action.

(Last edited by chacs on 8 Jun 2011, 17:39)