Well, I happens to the best of us sometimes. I flashed a WRT54G router with DD-WRT firmware and all appeared to be fine. Except when I attempted to make a client bridge to my other router using DD-WRT and after a reboot guess what? Kaput…the router would not connect to the computers lan connector. All lights on the router were on except for DMZ. I assumed that this router was going to make a nice black and blue paper weight.
So as stubborn as I am I decided to make some last ditch attempts to resolve my issues and revive my router. I have read many things online and some people have had some magical resolutions which revived their router. Some say they were able to short pins 15-16 on the flash chip and clear the nvram. I must say this is dangerous and can completely damage your board. If you smash the pins you can damage the flash chip and then you can call it over. It is suggested that you use the jtag method. Why? Because it has a higher success rate. If your afraid of soldering have an experienced friend assist you. Or play around with it your self. What do you have to lose it’s already not functioning the most you can do is make it work.
But I must say that the best solution has to be the jtag solution. On eBay I went looking for a serial cable that would help me connect to my dead router. Buying the parts and trying to make the cable my self would have been a fun project but I lacked the time needed for that.
Once all my tools arrived I needed to open up the router and locate the jtag port so that I can solder the 12 pin header to the board. The jtag ports are located on the left hand side of the board (If your looking at the 5th picture in the gallery). But before I could do this I would need to desolder the area making sure to have clean connections. Once this has been cleaned up I was able to insert the pins and solder the pins to the back of the board. I used some radio shack brand desoldering braid. Not very good at picking up solder even while very hot but still got the job done. I would recommend not using this type.
Ok. That takes care of the hardware issues but does it work? Well not at first. I needed to check a few of my solder points and ensure I have done a good job before the software would recognize my work. I had a solder blob which I needed to clean up. Only then I was able to probe the router using jtag3 executable program. Another issue was finding a computer with a parallel port. Im glad I still had an old computer around which was at my disposal. After a successful probe I backed up my cfe and cleared the nvram and erased the kernel. I issued only three commands. Like magic the lights turned off and then back on again with only one flashing light. I knew this was a good sign so I pinged the router and success it worked.
So finally I gathered my ddwrt firmware and uploaded it via tftp. Finally I was able revive this dead router that anyone would have tossed in the trash. Some side notes the Mac addresses are not correct they were automatically assigned. This can pose an issue for future networking projects where correct values are needed. As for my particular use I am satisfied with using it as a repeated bridge. When compared to my pcie wifi card I notice some speed improvements. I have a rosewell which has also been flashed with ddwrt firmware and for the value performed exactly as advertised. However these linksys routers have a reputation for excellence and I can agree as to why. The speed of the linksys was significantly better than the rosewell.
Instructional Video Coming Soon.