[fede06]

hi, a friend give me a wr841 for try to fix it, the problem was that he tryed to load a firmware for the V7, but this router is the V8, so the result, the power led stay on, and the rest just flashing every second, you know..

i saw several post which explain how to unbrick the router mounting a tfpt server, some with ip 192.168.0.66 and 88 i think, others whith 0.1 and 0.100 and doesn't work either, so i plugged a serial converter which i use to program an arduino to see if this has another couple of ip adresses, but only read weird stuff like the image




any idea?

[ramblin]

IMO the ver.8 is the most fussy of them all. Follow this link, scroll down to "TFTP recovery via bootloader for v8,v9,v10,v11,v12". Its the best tutorial.
https://wiki.openwrt.org/toh/tp-link/tl-wr841nd
I usually recommend this vid.
https://www.youtube.com/watch?v=0k1sxwX5pMk&t=4s
Either one should get you thru. Just curious, What operating system are you using to access the router?

[fede06]

i'll check those links again just in case i missed something, but i already tryed whith both.. the problem is the 3th step, no matter how much time i press the reset button on the start, the leds always make the same patron and the router doesn't load nothing from the tftp server

i'm using windows 8.1 whith the sercomm software, y also try with putty, but nothing.. i tryed the sercomm with my personal wr1043nd router and works like a charm, that's why i think this 841 it's so bricked that even can't read the serial

[ramblin]

As long as its bricked and not blown you should be able to recover it. Where you are at now is the hardest point to get past. I asked which OS as my Win 10 has given me a fit at this point before. My old XP machine would go right thru first time. Can`t speak for Win 8.1 though.

[fede06]

it doesn't work.. i rechecked both links and nothing, the leds do always the same pattern, no matter if i press the reset button 3 seconds on the start or if i don't do it, i tryed with every LAN port, even with the WAN just in case

the tftp program doesn't do anything

and the network interface change between the values: "unplugged cable", "unidentified network", "plugged cable" and "identifying network" every half second

[ramblin]

IMO, If it was blown from a power surge on the line or lightning you may have a led lit or nothing. The fact that it recognizes a cable being plugged or unplugged tells me it still can communicate. Ver.8 IS problematic.

[fede06]

[jone531]

Hate to dig up an old Necro post , but, I am experiencing the exact same issue.

Yes, I am new to the forum.. I am Andy, in the Atlanta area.. Thanks for having me...

Finally found a DD-WRT compat router at a local thrift store for $3.29.. how could I say no...

The Router is about identical to the one talked about here. A TP-Link WR-841N , HW Ver 8.4.

I put DD-WRT on there with no trouble at all. Ran great. In the spirit of messin around with this stuff, I wanted to revert back to the TP-Link OEM firmware.

This is where the trouble began. I followed this link to a T:

https://www.dd-wrt.com/wiki/index.php/TP-Link_TL-WR841nd_v8

Ran mtd -r write /tmp/tplink.bin linux and hit enter.

At the end of the process , it had an MTD erase failed error..I ran it 3 more times with the same results.

I tried to log into the GUI to modify the remote management settings , but the login screen was just a blank white page.

Did the 30-30-30 reset multiple times, only to end up with the flashing lights indicating that I now own a $3.29 Brick.

So , according to an article here, as well as on Open WRT, should be able to recover by setting up an TFTP server , boot the router to it and it will upload the correctly named flash image.

This where I have hit a wall. I Cannot get TFTPD64 to see my known good NIC that I have statically assigned 192.168.0.66 to. This running in Win 7 64-bit. I have disabled all other NIC's in the system. In NIC properties, I only have TCPIP v4 checked and QOS Packet scheduler.. Restarted the system and reinstalled TFTPD64 multiple times.. The only IP's that are avail appear to be in the 192.168.1.xxx range.

I think if I could just get this dang TFTP server configured, I might be able to get somewhere....Any and all input is appreciated...

[jone531]

Oooof, boy do I deserve the azz-hat award...This suddenly obvious thought just occurred to me...

NIC's not active with nothing connected , why would the IP be made avail??!!



I think when I go home , I'll throw one of my little active desktop switches in the middle, and I think I may have better results...

Now my only concern is that those dang LED's flash the same way , regardless if I hold the reset switch in or not... Hmmmm....

[ian5142]

Try the WPS button instead. It may not be the reset button.

[fede06]

Ok, it's been awhile.. quickly update, i couldn't fix it and i don't remember what else i tryed to bring it back, but i remember the end

I read somewhere that is possible load an image directly on the chip who storage the router OS with a sort of chip programmer so i desolder it from the board hook some wires and i clamp it in a programmer who i get borrowed from a friend and upload a stock firmware. I never knew what was wrong, the connections or the programmer, i don't know. But when i solder the chip back on the board nothing good happened, the leds just stay on all the time and nothing else. Then i had to remove the chip again and not having the necessary tools was stressful, so i just let it there, it's a really cheap router.

Now is accumulating dust on the top of the closet until i move to another apartment and end it throwing it away

[ian5142]

I often use Serial to help debrick any of my Atheros units. Get one of these (USB-TTL 3.3V Serial Cable): https://www.adafruit.com/product/954
I use the serial to see what the router is doing. I actually flash the device using TFTP.


The openWRT page has a serial section.

I have never needed a SPI flash programmer.

[jone531]

Fede, sorry to hear the way it turned out...That sucks...

The WPS button is the same as the reset button on these..

I have seen quite a few methods to recover using the serial interface...I have a small small stack of Arduino Uno's and an Arduino Mega. And of course the local Microcenter sells the USB \ TTL converter..So May grab one of those if all else fails..

I figure if it's flashing at me , then there's still life in it somewhere...Now if the TFTP method fails , and the serial method fails, then and only then will I bring out the BFH.. Haven't reached that point yet..

[jone531]

Well on to part 2...No response from TFTP...

Wireshark reports the MAC as ff:ff:ff:ff:ff:ff , and occasionally some multicast packets...Sometimes Wireshark reports no traffic..

So we're moving on to serial port access. May put one of my Arduino's to use here for this.

[jone531]

I am now on the lookout to see if I can find an SOL (Serial Over Lan) app that can speak directly to a MAC address..

If anyone is aware of such an app, I am all ears(or eyes in this case)..