recently got hold of a WRT54G v4 (CDFA) from a friend of mine, and I wanted to replace the stock firmware (4.20.7) with the VPN version of DD-WRT v23 VPN. Following the instructions, I reset to factory defaults, and loaded the v23 mini build, which appeared to flash ok. I then reset the defaults in the v23 mini build and then tried to flash to v23 VPN. afterwards the router failed to reboot. Luckily Boot_wait was on so I tftp'd mini back onto the router no problem and tried again. same results. At this point, v23 micro and mini and v24 micro work with no problems. I got standard to boot once, but failed to reboot after I reset the defaults. No other v24 RC3 works on the router and results in having to do the pin 16 short out trick on the board in order to get the router to ping again. No official firmware seems to boot either. I've tried 4.20.6 all the way to 4.21.1 with the router failing to boot with all firmwares except for 4.30.5, which boots once and fails after a default reset. I've also tried the 30 second reset button methods and typing command in SSH to try to reset the defaults and NVRAM with the same results as above. The only thing I can think of is that there's something in the NVRAM or flash that is corrupted, or even faulty ram, but I'm not sure. One thing I'm noticing is it appears that the router will not boot any firmware above 2.5MB, including official linksys builds. It makes me believe that the other 1.5mb is either bad or filled with something that is not erasing, and the only thing I can think of at this point would be to completely erase the flash and hope the bootloader will take a new image. is there any way to do that outside of a jtag?