Hello, I have a TL-WR841HP v2.. I saw that it had similar hardware to the 941nd v6, so I installed the original tplink firmware for the 941nd v6.. It worked, then I tried putting the dd-wrt firmware from the 941nd v6 on it.. installation process followed and after it restarted it no longer works. 3 LEDs stay on and nothing else happens...
I accessed via serial to see what happened, but I didn't receive any feedback via serial.
Since you attempted using dd-wrt, you need to ask on their forums. OpenWrt is completely different than DD-WRT. Further, your device doesn't appear to be supported by OpenWrt, so you won't be using anything from the official OpenWrt project anyway.
Installation instructions are in the git commit, but it looks like the prerequisite is that the vendor firmware is up and running properly. There is no mention of debricking methods on the tech data page.
And since we (OpenWrt community members) cannot know what happens when you flash the wrong DD-WRT file to a device, and how to subsequently debrick it, you'll need to visit their site for more help.
If all of the LEDs come on and don't go out, and there is no serial output, the bootloader is not running at all. A likely reason for this is that the bootloader partition in flash has been clobbered by improper flashing. To recover you'd need hardware to write directly to the flash chip and re-install the bootloader. TP-Link usually includes a copy of the bootloader in the stock firmware file-- you can break down that file and flash the bootloader only.
Yes, that's what happened. The bootloader was corrupted, but I don't know how to extract the bootloader from the original firmware, could you help me with that?