Un-brick Linksys WRT54GL After Failed Upgrading to DD-WRT

When I directly load the Standard DD-WRT 24 SP1 into a brand new WRT54GL, it failed. After reboot, I lost the access to the router. Now whatever I do, the router's power LED just keep blinking. So I have bricked my new router! Further research tells that I should have upgrade to a DD-WRT Mini first, the information on the WRT54GL wikipedia page is misleading by saying that version 1.1 can go direct from Linksys firmware to 4MB 3rd party image, which is very wrong.

Again I searched about how to un-brick it. I have tried 30/30/30 hard reset, recvudp and etc. Non of them worked for me. It doesn't seem to have a direct answer to my situation. Information about using Windows XP is also very rare. But my research made me understood the WRT54GL better and it turned out that my situation was actually a bit better them some others.

Un-brick the router

Krunk4ever was the closest post I found but taking the router apart was not necessary for me. So here is the step by step instructions of what I did on a Windows XP to recover my router and hopefully save somebody some time.

1. Download the latest Linksys firmware to the PC and unzip it.
2. Directly connect the PC to router's LAN 1 port. Turn off any other wired or wireless connections on PC.
3. Go to the control panel -> Network Connections.
4. Right click on the Local Area Connection and select Properties. (if you have more then one Local Area Connection, pick the one is connected to router which should have limited connection now) 
5. In the property page, select the Internet Protocol and click on the Properties button
     
6. Select "User the following IP address" and enter 192.168.0.1 in the IP address text box.
   
7. Close all dialog boxes by clicking OK.
8. Open a command prompt, CD to where the firmware was saved in step 1.
9. Run command below replace the file name with the firmware that you have downloaded.
                tftp -i 192.168.1.1 put FW_WRT54GL_4.30.12.3_US_EN_code.bin
   You should get a response like below.
                Transfer successful: 2941952 bytes in 5 seconds, 588390 bytes/s
10. Do do anything now, wait for the route to restart by itself until you can ping it and then point your browser to http://192.168.1.1

Upon successful un-bricking, don't forget to revert the changes that you have made in the step 6.

Troubleshooting in the step 9

• If you get "Error on server : code pattern incorrect", then you have the wrong firmware file. Make sure you downloaded the right firmware.
• If you get "Timeout occurred", power down the router, wait for 10 seconds and power the router on. When the power LED started blinking, try step 9 again. If still doesn't work, then you are having a different problem then mine. Check the post at Krunk4ever.

Installing DD-WRT.

This time, I made sure to install the Mini version first and then Standard version, the installation was very smooth.