I've been running this router on dd-wrt for several years now. I wanted to try out OpenWRT, and was following this article - https://oldwiki.archive.openwrt.org/toh/tp-link/tl-wr841nd
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?