Apparently I didn't read well enough on my first attempt to install TomatoUSB on my E4200 and installed the wrong version. I installed "tomato-K26USB-1.28.9054MIPSR2-beta-Ext" which I can now only access the router via the Wifi interface. I am unable to pull an IP address or access the WebGui when I sent an IP. I have tried to reflash with DD-WRT, and the original Linksys OEM firmware and all I receive is an error message of "File contains an invalid header". I even tried to install the correct version of Toastman "tomato-E4200USB-NVRAM60K-1.28.0498.1MIPSR2-Toastman-RT-N-Ext" which results the same error. Any ideas how I can recover my router without a JTAG board?
I've never used a 4200 so I don't really know, but I'll make a suggestion.
I'm assuming you can install firmware via tftp? That's probably what you'll need to do since you can't do it in the web interface.
You can google "Recover from a bad flash" and come up with a lot of help with this situation. You should be okay with your router since you can still access it some what.
Sorry I have actually have tried tftp, rftp2 and I have also tried using Ubuntu bad flash recovery in linx method for the WZR-HP=G300NH.
There was someone on DD-WRT forums that was talking about a jtag connection but I do not know anything about jtags.
Sometimes jtag is the only way to recover if the router is bricked badly enough. It sounds to me like you'll be able to pull this one out though.
When you tried to tftp the firmware, was it after the device was up, or did you catch it during boot-wait? the window is small, so it's possible you missed it. I saw a DD-WRT thread that had some kind of script to run it. Also, I don't know if this is how the E4200 works, but if you boot up with the reset button pressed down, and then try and go to the page it may have a firmware update window. If not, try tftp for the same scenario. Good luck.
I keep getting a message that I am not allow to post links yet I am not adding one. Hmm anyways I found a solution
on the other forums which was to strip out the 1st 32bytes of the header so that it starts with HDR0. This seemed to work very well and now I am running the current version of tomato.