Check out this tutorial on debricking a La Fonera router:http://log.tigerbus.de/?p=89
DEBRICKING A LINKSYS ROUTER USING TFTP ON A WINDOWS 2K or XP LAPTOP IN SIX EASY STEPS:
by AustinTX, ver:060905
When your Linksys router’s power light is blinking continuously, it means that the router tried to load the firmware, but found that it was corrupt. It is still functioning. These instructions will help you to reload the firmware on the router in the same way it was installed at the factory. No tools are required besides a computer (a laptop is assumed), a working ethernet cable and a basic understanding of windows networking configuration and browsing web pages. It would be helpful if you read through this several times first so you are familiar with it.
1) [DOWNLOAD THE ROUTER FIRMWARES IN ADVANCE]
a) Download mini version of DD-WRT for your model fromhttp://www.dd-wrt.com/dd-wrtv2/downloads.php stick with V23 for simplicity here. You need to flash the mini version first to avoid running out of available ram.
(If you have a GL router, you want the G firmware version).
b) If you intend to use DD-WRT, choose the full version you desire and download it also,
-or- if you intend to reflash fonbasic, download it to the laptop from http://en.fon.com/downloads/
c) Rename the DD-WRT mini file to “code.bin” (optional)
2) [CONFIGURE LAPTOP CONNECTION]
a) Disable your laptop’s wifi and configure laptop’s wired network for: IP 192.168.1.10 Subnet 255.255.255.0 Gateway 192.168.1.1
b) Connect laptop LAN to router LAN #1 using ethernet cable
3) [START PING AND GET TFTP READY]
a) If your router is powered up at this time, unplug the power cord now.
b) Open a DOS window and type: “PING -t 192.168.1.1″ . Ping will fail while the router is off.
c) Open a second DOS window and type: “tftp -i 192.168.1.1 PUT code.bin” (or real filename if you didn’t rename it)
(Linux equivalent: tftp -v -m binary 192.168.1.1 -c put code.bin )
4) [UPLOAD MINI FIRMWARE]
a) Arrange your DOS windows so that you can see both of them at the same time. Make the TFTP window your active focus (“on top”).
b) Plug power cord into router.
b) When pings begin replying in the first DOS window, immediately press enter in the TFTP window.
You should see a status message about the download, or an error message.
Example error: “Code pattern is incorrect”. This means that the firmware image you selected is intended for a different model router.
Example error: “Invalid Password”. This means that the TFTP server you are using doesn’t support some requirement of the router’s TFTP client. You may wish to use a computer with a different operating system on it, or Zargon recommends Pumpkin as an alternative: http://kin.klever.net/pumpkin/binaries
The TFTP upload needs to occur within a five second window, so you may not be successful the first time!
An alternate method Deedander describes may work better if you are unable to upload after a few tries. Instead of connecting your laptop’s ethernet port directly to the router’s LAN #1, use two ethernet cables and connect these ports through a hub or switch. The LED for your laptop should light up and stay on. Instead of waiting for pings to reply in your laptop’s DOS window, you will watch the link LED for the hub port you have connected the router to. Plug the router’s power in and start your TFTP server as soon as that LED comes on. See his tutorial at:https://web.archive.org/web/20080515210639/http://boards.fon.com//viewtopic.php?t=1893
Using a hub/switch in between the bricked router and the laptop may be why some tutorials reccomend “If using a 10/100 network adapter, change its speed to 10Mb, half duplex.”
Don’t touch anything. The router will eventually reboot itself.
5) [REFLASH WITH FULL VERSION USING WEB INTERFACE]
a) Access the router’s DD-WRT web config page at http://192.168.1.1 (username is “root” and password is “admin”)
b) Click the “Administration” tab and then the “Firmware Upgrade” tab.
c) Select “default settings” and click “Browse” button
d) Find the fonbasic or DD-WRT_Standard firmware file of your choice and select it.
e) Click Upgrade button
Don’t touch anything. The router will eventually reboot itself and you will be able to return to the local management pages.
Linksys routers have finished when the DMZ light stays off, and if this is a GL router, the amber Cisco light stays on.
6) [RESTORE LAPTOP WIFI and DHCP]
a) You will need to set your laptop to get an IP automatically again,
b) And may need to reboot your laptop afterwards.
c) Disconnect the ethernet cable and re-enable wifi. You should be able to find the “DD-WRT” or “Fon_” SSID and associate with it. If you have reflashed to fon firmware, you should get an IP address in the 192.168.182.* range, and your web browser should be redirected to the fon login page.
Credits: based on another web tutorial by Unknown:http://www.freewebs.com/wrt54grevival/wrt54grevial.htm.html
Revisions: Changed “micro” to “mini” as micro DD-WRT firmwares are not always offered.
Fixed spelling and grammar errors, capitalized sentences.
Explained “Invalid Password” error message per chosenone85.
Added alternate connection method using a switch per Devedander.
Added reccomendation of alternate TFTP server software per Zargon.