Another bricked and rescued Archer C8v2

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Felpas
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Joined: 20 Aug 2024
Posts: 1

PostPosted: Wed Oct 16, 2024 8:55    Post subject: Another bricked and rescued Archer C8v2 Reply with quote
I'd like to share my experience with my Archer C8v2. After flashing the factory-to-ddwrt.bin file in my Archer C8v2 (appartently without errors) the router went into bootloop.

I tried to install the OEM recoveries using the recovery mode using TFTP64 (Firm renamed to: ArcherC8v1_tp_recovery.bin) with the PC IP set to 192.168.0.66/24, pressing the reset key while booting the router, this forces the recovery mode, and the firmware should be flashed via TFTP automatically, in my case without success). I even tried to install the recoveries via TFTP with commands, but still no success.

I also tried to install the dumps I found in the forum using Putty and TFTP64, after doing that I got the error:

"Could not load flash0.os:: Unsupported function"

And... I thought it was finally hard bicked. In another post of this forum I saw that it was necessary to remove the flash memory chip and write a flash dump in order to recover it. This was not an option for me.

So... since I had nothing to lose, I checked in Putty (SEE step 3) that the router IP was not the one of the original firmware (192.168.0.1) but the one that DD-WRT gives by default (192.168.1.1) I decided to flash the DD-WRT firmware build "02-23-2021-r45820" (ONLY the "archer-c8v2-webflash.bin" file, NOT the "factory-to-ddwrt") via Putty - TFTP, so I renamed it with the name of the Linksys OEM firmware: c8v2_un-up-ver4-0-0-P1[20160520-rel62091].bin and voilà, the router was alive again and with DD-WRT firmware.

I used as a reference a youtube tutorial on how to unbrick Archer C9 using Serial-USB connection.

Previous steps:

- Install TFTP64
- Install Putty
- Install USB uart drivers - Silicon labs CP210x

- Configure COM Port in Putty with the corresponding number (confirm in devmmgmt.msc E.g. COM3) with the following options:

- Speed ​​115200
- Flow control - none

- Configure the network adapter IP to 192.168.1.66/24 (or 192.168.0.66/24 depending on the router IP - SEE Step 3).
- Connect router via RJ45 to port 1 of router
- Connect to serial port as follows using a pogo pin clip, so you don't have to solder anything on the board (4pin 2.54mm) (see attachment).

Steps to recover router from soft brick:

1 - Turn on the router with both TFTP64 and Putty open.
2 - Stop the booting process by clicking ctrl+c (in Putty) until CFE> appears on the screen.
3 - Use ifconfig command to see router IP.

If we have flashed the "factory-to-ddwrt.bin" the IP should have changed to 192.168.1.1 (the original firmware is 192.168.0.1), double check it anyway.

4 - Download the build 02-23-2021-r45820, we only need the file "archer-c8v2-webflash.bin" renamed to archer_c8v2_un-up-ver3-17-0-P1[20150716-rel55646].bin then flash it using the following command in Putty (the file should be located in the TFTP64 folder):

flash -noheader 192.168.1.66:archer_c8v2_un-up-ver3-17-0-P1[20150716-rel55646].bin flash0.trx

Result:

CFE> flash -noheader 192.168.1.66:archer_c8v2_un-up-ver3-17-0-P1[20150716-rel55646].bin flash0.trx
Reading 192.168.1.66:archer_c8v2_un-up-ver3-17-0-P1[20150716-rel55646].bin: Done. 12906496 bytes read
Programming...done. 12906496 bytes written
*** command status = 0

4. Reboot the router.

With all this, I tried to make a complete guide (more or less) about unbricking an Archer C8v2 because I found lots of information, but all spreaded around. If this helps someone and saves you few hours of reading docens of posts I'd be happy.[/img]



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