Help Needed: TP-Link Archer C20 AC750 (US) v6 Bricked After Incorrect OpenWrt Flash

[stereotype]

Hello everyone,

I'm reaching out for some help with my TP-Link Archer C20 AC750 (US) v6 router. I was attempting to flash OpenWrt onto it using TFTP, but I accidentally used the firmware for version 4 instead of version 6 from https://openwrt.org/toh/tp-link/archer_c20_v4. After the flash, my router rebooted, and now the only light on the router is the LAN light when it’s connected to my computer via Ethernet. When I disconnect the Ethernet cable, all lights on the router turn off.

Here’s what I’ve tried so far:

1. TFTP Flashing: I’ve been able to connect to the router via TFTP and attempt to flash it again and again using OpenWrt .bin files to no avail.
2. Original Firmware: I’ve also successfully flashed the original TP-Link firmware multiple times, but the router still isn’t working at all, only the LAN light remains on when connected to my computer.

Despite these efforts, the router is still not operational. I’m not sure if the incorrect firmware has caused irreversible damage or if there’s a different approach I should try.

Has anyone experienced a similar issue or have any advice on how to recover the router? Any help would be greatly appreciated!

Thanks in advance for your assistance!

[frollic]

@stereotype

I’m not sure if the incorrect firmware has caused irreversible damage or if there’s a different approach I should try

serial console ...

[stereotype]

What do you mean by your comment "serial console"?

[frollic]

there's usually serial console access somewhere on the PCB, you need to find it, and connect to it, using an USB TTL.

not sure if these photos apply to you to, since OP wrote he had a C20W.

New Archer C20 v6. Serial and support needed

Hello! I recently got this unit. Seems almost identical to the v5 (which works perfectly fine with OpenWRT) except for the 5G Chip and the fact that this one has 4 antenas (v5 has 3 antenas). Internally seems that 2 antenas are for 2G and the other 2 for 5G Photos: https://imgur.com/a/Wb2xAw8 Also, wanted to post a boot log but I'm unable to get output. Soldered the 4 pins, photos: https://imgur.com/a/kreJZrm From right to left and far right being the one with the printed triangle im connec…

[stereotype]

I don't really have experience with that, are you sure that's the only way? I can still TFTP to my router and everything.

Edit: I'm also not sure how I can make use of the "a full serial bootlog + MTD info " post on there that apparently people found useful.

[frollic]

@stereotype

I don't really have experience with that,

then you'll learn something new

@stereotype

are you sure that's the only way?

no, but there's no other way to find out, if your TFTP flashes fail...

@stereotype

I can still TFTP to my router and everything.

it means the boot loader is intact, which is good.

where did you find the v6 images anyway, I can't see it being supported ... ?

[stereotype]

My TFTP flashes are successful, the router is just not working.
I was even able to successfully TFTP flash the original TP-Link firmware from their website on it and it was 100% successful yet the router still doesn't work like all lights are off except for the LAN cable light when I have it connected via ethernet to my computer.

In regard to the v6 images, as I wrote in the original post above, I used the v4 images mistakenly thinking those would work on my v6 after reading someone's comments on that.

[frollic]

What additional info do you need ?

Get serial, or keep fumbling in the dark.