I tried this today with a TP-LINK TL-WR703N 20130703 but it looks like it bricked it. After the flash I couldn't connect to it at all. Also, unlike the routers in the Avalons or a Raspberry PI it required an external power supply to work but when I used it the Avalon wouldn't power up at all. Am I missing a hardware mod or something?
Was happily running 20130703 since release with no issues at all. Highly recommended (on 20 or so units - batch 1 and 2, on my batch 3's I just run stock because of the temp sensor change etc). I saw the new firmware and decided to give it a shot on a batch 1 and it bricked it. No reset or nothing could get it back.
I figured no problem. I picked up some extra TL-MR3020 to replace the TP-LINK TL-WR703N router but those didn't flash and in the end I gave up on messing with that (from what I can tell you need a custom one or something).
A retail TP-Link 703n can be found on eBay or Amazon for about $20. It can be flashed with the 20130703 firmware, and then plugged into the USB cable inside the Avalon. The LAN cable or WiFi can be used to access it. It has a mini-USB power cable. I ran a for-repair Avalon a few hours this way before I got the soldering iron and made a permanent repair.
I used the re-flashed retail unit with no hardware modification for an hour or so. The mini-USB supplied power. The Avalon USB plugged into the side. I removed one of the screws from the top of the Avalon and fed the USB cable through the slot, and mounted the TP-Link outside the case.
I later modified this unit, I removed a 0R resistor to disconnect the internal antenna, and added a 0R resistor to backfeed power from the Avalon USB connector, and added the antenna, and replaced the dead internal unit, and closed it all up.
Does the blue light stay on with your TP-Link? If you push the reset button while it is starting up, does the blue LED flash about twice/second?
Are you trying to connect via the LAN jack? I think the WiFi has to be configured.