However, upon flashing the recommended firmware, the router became unresponsive, and would not assign a LAN address. After several 30-30-30 resets, I tried the tftp unbrick process recommended. No firmware appears to have been installed, but now, the router does not even boot fully. If I power it on and hold down the WPS button, the lock LED stays lit, and no activity occurs in TFTP. If I let go, the power LED comes on and stays on, no other activity. Manually setting an IP address of 192.168.0.66 and scanning wireshark shows no router activity.
I've purchased a Serial TTL adapter and soldered pins in the appropriate places, but I get no activity in the console. Is there anything else I can try, or is this router well and truly dead?
For your info, the page you mentioned is the old Wiki, and isn't maintained. I am not sure what version you you're to flash.
This is the current page for the device https://openwrt.org/toh/tp-link/tl-wr841nd. A quick look suggests the content is very similar (which is expected, as it's an old device), but it wouldn't harm if you have a look there and see if it adds anything.
If the "lock" (WPS) LED comes on when you boot with the reset button held down, this should be TFTP recovery. Note that to run a TFTP server on Windows you have to turn the windows firewall off.
On this model there is a missing resistor which prevents the serial port from receiving anything from the PC. You need to solder a small wire across the two pads for R23 or if you're really good, install a small resistor there of maybe 47 ohms.
Thanks for the info. In TFTP mode, should it be showing some type of LAN activity? I will try turning the firewall off entirely, I've only added exceptions so far.
I am not that good =) I will try jumping R23 though
