[HELP] Router DD-RWT dirty flash
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[HELP] Router DD-RWT dirty flash

Hello there

I was upgrading my wr940nv1 but accidentally downloaded wr941nd ddwrt file and now the router is in bootloop

I really have no experience in setting up serial connection ...

On YouTube people have been able to flash router firmware without serial connection using tftp server

I tried the tftp method But this doesn't work at my end :-(

Any suggestions

Thanx in advance

Comments

  • deankdeank Member

    Have you tried contacting the youtubers?

    Blackboyfriend (BF) is nigh. Always pre-pay for 3 ~ 6 years. You will regret it. And vote for Fran in 2020.

  • smilesmile Member

    either set up a serial connection or recycle it in your local bestbuy,etc.

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  • lemonlemon Member
    edited October 30

    I think you're better helped by asking in the ddwrt forum

    i did NAT

  • OseriOseri Member

    Read your router manuals to find if it have some recovery/failsafe/emergency procedure to allow upload a recovery firmware image. I recall D-Link ones have this but (I used it in the past) not sure about TP-link.

  • To be clear it's easy to recover with tftp server, I have several times repaired mostly dead routers. Google for tftp wr940nv1. It's super easy. Whole logic in next: router has some mode which allow you to automatically upload router image to the rounter after pressing and holding power button (or reset, depends on the router) and emulating tftp server and client, and rounter will automatically when boot catch the ISO and will install it. Than it will install it. And for future: NEVER EVER UPGRADE ANY FIRMWARE FLASH, tplinks very bad routers in this terms.

  • lurchlurch Member

    tftp is the best method google for your device or "tp-link tftp" you can run a server on your windows or linux machine then it's just a case of setting the right ip's and filename. Then normally you hold the reset button in and power or on (or something similar) to put in tftp mode.

  • @desperand said:
    To be clear it's easy to recover with tftp server, I have several times repaired mostly dead routers. Google for tftp wr940nv1. It's super easy. Whole logic in next: router has some mode which allow you to automatically upload router image to the rounter after pressing and holding power button (or reset, depends on the router) and emulating tftp server and client, and rounter will automatically when boot catch the ISO and will install it. Than it will install it. And for future: NEVER EVER UPGRADE ANY FIRMWARE FLASH, tplinks very bad routers in this terms.

    I have updated firmware many times

    I guess my luck ran out

  • Check https://openwrt.org/toh/tp-link/tl-wr940n

    TFTP should work. Some of my usual mistakes include

    • Forgetting to put TFTP server in "binary" mode.
    • Not waiting long enough for recovery - wait like 5 minutes for the entire process (upload to finish, LEDs to flash and reboot to complete).

    Maybe a 30-30-30 reset will help

  • @rincewind said:
    Check https://openwrt.org/toh/tp-link/tl-wr940n

    TFTP should work. Some of my usual mistakes include

    • Forgetting to put TFTP server in "binary" mode.
    • Not waiting long enough for recovery - wait like 5 minutes for the entire process (upload to finish, LEDs to flash and reboot to complete).

    Maybe a 30-30-30 reset will help

    How do you put TFTP server in binary mode

    using win 10 and tftpd64 by Ph.Jounin

  • netomxnetomx Member, Moderator

    Easiest way to flash it is connecting via serial, as you can see exactly what is going on

  • How do you put TFTP server in binary mode

    tftpd64 might use binary mode automatically. I have only used Linux tftp.

    BTW, Are you sure you are booting router into recovery mode? Pull out the plug, and with the "reset" button pressed plug it back in. Wait for 5 to 15 seconds and the LEDs will start blinking or you might hear a beep. Then release the "reset" button. Also make sure ethernet cable from PC is plugged on a LAN port of router, and not the WAN port. With your IP address set to 192.168.0.x ping the router on 192.168.0.1. If that works, then TFTP transfer should also go through.

  • https://forum.tp-link.com/showthread.php?81462-How-to-recovery-the-router-when-you-bricked-it

    Follow and adapt it to your router. Not that hard, and fixes the damned thing. Then put it back in the box and get a real router. TP-Link has gone to shitballs lately.

    Dont'TalkAboutLetClub Sensei of the Yeti Assassins Anyone see where I parked @jar car?

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  • My country is in lockdown and I can't get to the nearest electronic shop to get USB UART
    Otherwise it would have been easy

    @AuroraZ said:
    https://forum.tp-link.com/showthread.php?81462-How-to-recovery-the-router-when-you-bricked-it

    Follow and adapt it to your router. Not that hard, and fixes the damned thing. Then put it back in the box and get a real router. TP-Link has gone to shitballs lately.

    I have couple of users and most of the devices are n only only I have one 5ghz device (but not ac) and only one AC ....

    Upgrading router is not justified . obviously if i couldn't recover it then that would be the way to go :-)

    1. Download: from Mega whole archive with image and tool what you need to use

    2. Connect to your router via LAN cable and your ethernet adapter on laptop or PC

    3. On laptop or pc set IP: 192.168.0.66, mask: 255.255.255.0
    4. Turn off all firewalls/antiviruses, etc to make sure that you will have a connection from the router.
    5. Turn off your router.
    6. Run with admin privileges tftpd32.exe
    7. Server Interface: select your Ethernet Adapter where you will see your 192.168.0.66 or 192.168.1.66 above.
    8. Click on ShowDir: you must see there your image wr940nv1_tp_recovery.bin
    9. Hold Reset Button and do not stop keep holding it.
    10. Turn ON your Router.
    11. Then, if IP above is correct (try first 192.168.0.66) and the router is not badly damaged - router will try automatically download the image on itself from your device and install it (you will see uploading status)
    12. Than if uploading success, do not touch router for 120-180 seconds
    13. Then the router would work.

    Just screenshots

    Thanked by 1Janevski
  • Update

    Router Fixed finally

    Few things if anyone stumbles upon this thread

    WR940NV1 or WR941NDV4

    Easy Method

    TFTP Server via Recovery Method

    Methods mentioned above simply doesnt work in this model

    Little Difficult Method

    You need to solder headers to RX TX and GRND and use a USB to 3,3V Serial Adapter

    Note the serial port on the right part of the board, approx. in the middle. Four pins next to the two large capacitors.

    The serial port pinout is TX, RX, GND, NC. (in the picture from bottom to top)

    you can always use a Digital Multi meter to verify this

    Use this layout

    USB <--> Router Board

    RX <--> TX
    TX <--> RX
    GRND <--> GRND

    Next Step

    use Putty and Setup this as follows
    Com Port : accordingly
    Baud Rate 115200
    Data bits 8
    Stop bits 1
    parity none
    flow control none

    Next power up the router and login in..

    if you have done everything write you should start seeing U boot interface

    if not

    check if pins are soldered properly and usb to uart ttl drivers are correctly installed

    Now the router is in boot loop and will give you only 1 sec to stop it

    You have to type "tlp" and it will stop

    Note: on some models you can use Ctrl + C

    This can be annoying some time as you have to get this right

    Next Step is simple

    type "printenv"

    it will give you server ip and its own Ip address

    for WR940NV1 The parameter values are

    ipaddr=192.168.1.123
    serverip=192.168.1.100

    bootargs=console=ttyS0,115200 root=31:02 rootfstype=jffs2 init=/sbin/init mtdparts=ar7240-nor0:256k(u-boot),64k(u-boot-env),2752k(rootfs),896k(uImage),64k(NVRAM),64k(ART)
    bootcmd=bootm 0x9f020000
    bootdelay=1

    Now you need to connect it to a computer using the prefferably eth0 i.e the first lan port

    Setup static Ip the value of serverip will be yourcomputer ip and the parameter ipaddr will be your gateway

    subnet mask is simple 255.255.255.0

    Now you have to setup tftp by Ph.jounin

    Open tftpd on your computer

    select the correct interface
    select the directory with the downloaded firmware from tp link website.
    Rename the file to firmware.bin

    Next switch back to putty and type this command

    tftpboot 0x80000000 firmware.bin

    Now if you have done everything correctly the file will be uploaded.

    Now it will give you a file size of file uploaded in Hex

    This is important !!! Save it

    Next Step is to get the correct hex address for flashing

    type printenv bootcmd

    bootcmd=bootm 0x9f020000

    the address in hex will give you the address

    Next Command is this

    erase.b 0x9f020000 +0x3c0000

    The first parameter is the hex address and the secondparameter after + sign is the filesize

    if you enter incorrect hex value or file size the router will be again in bootloop

    next step is copying the flash

    type

    cp.b 0x80000000 0x9f020000 0x3c0000

    again adjust parameter according to your values

    if all these commands didnt gave you an error you are ready to test your router
    you dont need to disconnect the router a better way is to type this command

    bootm 0x9f020000

    again adjust the value accordingly

    if the flashing was correct you should start seeing the router booting up properly.Also look at the router leds

    if the flashing was incorrect then the router would be again in bootloop

    This means the three important commands

    tftpboot 0x80000000 firmware.bin
    erase.b 0x9f020000 +0x3c0000
    cp.b 0x80000000 0x9f020000 0x3c0000

    you made a mistake of hex value
    or the firmware you are flashing again is corrupt

    This is just a rough guide written in 10 -15 mins

    Thanked by 3rincewind eol Janevski
  • lurchlurch Member

    It's tpl not tlp

  • oneilonlineoneilonline Member, Provider

    That was an impressive read. I would have taken the easy route (pun intended ;) and just went and bought another one.

    Thanked by 1NanoG6
  • Good job with this one. I keep a handful of USBTTLs (PL2303HX to ya motha) around for just these sort of projects.

    Limited quantity. May expire at any time.

  • Very nice thread. Although a little complicated, serial connection is always helpful.

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