So I tried updating to DDWRT from the latest stock firmware. Flashed the .chk file from http://www.myopenrouter.com/download/16365/DD-WRT-for-WNR3500L-v24-K2.6-Mini-CHK/ and now my router appears to be bricked, won't even assign my computer an IP address. Is there any way to fix this without having to buy a serial cable?
Possibly.
You need to first make sure you are connected wired to the router, not wireless.
Then setup your computer to a specific address like 192.168.1.10, 255.255.255.0 and gateway to 192.168.1.1.
If not sure how see here for windows. http://www.hotcomm.com/faq/FAQ_staticIPXP.asp If you run something else then you will need to figure out to do it with that OS.
Then when done try and ping the router at 192.168.1.1 if you get a reply then first see if your web browser will show you anything at 192.168.1.1
If not see here on how to tftp a new firmware back on. http://www.myopenrouter.com/article/13702/Recover-Your-Bricked-NETGEAR-W... Although it talks about the WNR router the bacics are the same for the WNR router too.
You will have to tftp a CHK firmware not a BIN firmware back to the router.
The 30-30-30 hard reset fixed it, thanks for the help!