Tp-link Archer C8 - bricked

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epyshor
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Joined: 07 Sep 2017
Posts: 6

PostPosted: Thu Sep 07, 2017 6:07    Post subject: Tp-link Archer C8 - bricked Reply with quote
Hi, i hope i posted in the correct place.
I'm looking for a complete flash dump of a Archer C8 V1.0. (EU)

i was flashing firmware from cfe but forgot the offset so i think i managed to override my bootloader with a nice trx linux partition Crying or Very sad

leds are not all blue,
no network activity(wireshark),
no cfe console on uart,
no recovery tftp,

Leds on: lan (blue), usb (blue)

wished i made that eeprom dump before the flash Shocked

i think for recovery i need a full spi dump of a eu model Archer c8 v1.0

for the dump i made after i had to de-solder the flash.

Hope you can help me Smile or give me some closure Crying or Very sad



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Last edited by epyshor on Thu Sep 07, 2017 8:57; edited 3 times in total
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Montago
DD-WRT Novice


Joined: 08 Sep 2017
Posts: 4

PostPosted: Fri Sep 08, 2017 7:42    Post subject: Reply with quote
I might be able to help...

i'm interested in upgrading my Archer C8 V1 myself so i guess it would be good practise to make a backup first Smile

i don't know how to make a EPROM Dump - do you have a link how to ?
epyshor
DD-WRT Novice


Joined: 07 Sep 2017
Posts: 6

PostPosted: Fri Sep 08, 2017 8:00    Post subject: Reply with quote
Montago wrote:
I might be able to help...

i'm interested in upgrading my Archer C8 V1 myself so i guess it would be good practise to make a backup first Smile

i don't know how to make a EPROM Dump - do you have a link how to ?


you must to desolder the flash memory from the board. do you have the tools ?
also, you need to have a spi writer/reader 3.3v ( raspberry pi or other )
Montago
DD-WRT Novice


Joined: 08 Sep 2017
Posts: 4

PostPosted: Fri Sep 08, 2017 8:02    Post subject: Reply with quote
In that case, i can't help Sad

Just buy a new router, here in DK you can get one for 100$
ptuMb
DD-WRT Novice


Joined: 21 May 2020
Posts: 13

PostPosted: Tue Jun 02, 2020 21:30    Post subject: Re: Tp-link Archer C8 - bricked Reply with quote
Hi,
epyshor
Have you managed to fix that C8?
Can you send me a full dump if you have please?
Preferably with the stock firmware on it.
I have screwed up my boot loader too.

Why do you have to desolder it?
Can you not read write the flash on the board?
Can I just solder wires on the legs without removing the chip?
msoengineer
DD-WRT Guru


Joined: 21 Jan 2017
Posts: 1244
Location: Illinois Moderator

PostPosted: Tue Jun 02, 2020 22:37    Post subject: Reply with quote
before doing all that, what happens if you connect to the router via lan cable and run wireshark?

Can you see any output looking for tftp?
see a guide here for wireshark:
https://crosp.net/blog/hardware/unbrick-tp-link-wifi-router-wr841nd-with-tftp-wireshark/

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ptuMb
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Joined: 21 May 2020
Posts: 13

PostPosted: Wed Jun 03, 2020 16:17    Post subject: Reply with quote
msoengineer wrote:
what happens if you connect to the router via lan cable and run wireshark?

Can you see any output looking for tftp?


Hi
I've been playing cowboy style desperately trying to revert dd-wrt to stock. I have tried a few things and at one point the router has a stock Archer C9 firmware on it that actually was working (I only briefly tested it though) but I kept playing around trying to make it a C8 again and finally I have killed it.

At the moment there is a different CFE on the device than originally. Don't ask me how it got there Very HappyVery HappyVery Happy Mr. Green

Through serial terminal I can see the CFE starts its thing but halts with a message:
Waiting for reset button release...

I have managed to throw the wrong CFE on it as it looks and it expects a different hardware with the reset button on a different pin hence it thinks something is holding the reset button.
And I'm lucky the factory fitted smoke has not been released yet.

CTRL+C doesn't cancel the booting process because the CFE halts before it gets there.

I have a save of my original CFE but there is no jtag header on the motherboard and I couldn't find much info how to trace the PCB for possible solder points.

Wireshark shows no signs of life either.
So yeah I think I'll have to get a flash dump from someone or buy another router.
delhite2
DD-WRT User


Joined: 04 May 2009
Posts: 78

PostPosted: Fri Jul 03, 2020 21:39    Post subject: Dump file Reply with quote
If anyone got the dump for C8 v1, please post it or share it with me, I don't have serial output on my device, need to flash the spi chip again.
tia

EDIT: flash dump found and attached. It is for C8 v2, but i have loaded it to c8 v1 without any issue

UPDATE: flash dump for C8v1 attached.



C8v1_fulldump_stock.zip
 Description:

Download
 Filename:  C8v1_fulldump_stock.zip
 Filesize:  14.42 MB
 Downloaded:  80 Time(s)


archer c8 full dump v2.zip
 Description:

Download
 Filename:  archer c8 full dump v2.zip
 Filesize:  10.52 MB
 Downloaded:  61 Time(s)


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kernel-panic69
DD-WRT Guru


Joined: 08 May 2018
Posts: 7178
Location: Texas, USA

PostPosted: Sat Jul 04, 2020 2:20    Post subject: Reply with quote
REF: forum.dd-wrt.com/phpBB2/viewtopic.php?t=283416

ptuMb wrote:
I have played around with the C8 a lot to figure out a way of reverting it to stock without the need of taking the router apart and here is what I found working.

PLEASE NOTE! Flashing the bootloader can BRICK your router and the only 2 ways of recovering (JTAG or flashing chip with external programmer) they both involve taking it apart and a lot of headache. It is also not recommended to flash the CFE bootloader through SSH/telnet/webGUI and this is the very thing we are going to do here! Although this worked for me it may not going to work for you so DO IT AT YOUR OWN RISK!

1. Install and run a tftp server on your PC.

2. Download 2 files and put them in the tftp directory:
- the c8v1_cfe.bin file from this post
- the firmware from TP-LINK website and rename it to ArcherC8v1_tp_recovery.bin

3. You need to run some terminal commands and you have 3 ways of doing that:
- SSH connection
- Telnet connection
- through ddwrt webGUI ( Administration-> Commands )

The first command saves the current CFE from your router and the following 3 will flash the new one.
Be sure include the ; at the end of each line as the webGUI has a bug. Without the ; it will mess up the commands.
(192.168.?.??? is the tftp server IP address)

Code:
tftp -p -l /dev/mtd0ro -r cfe_backup.bin 192.168.?.??? 69;
tftp -g -l /tmp/c8v1_cfe.bin -r c8v1_cfe.bin 192.168.?.??? 69;
mtd unlock /dev/mtd0;
mtd -f write /tmp/c8v1_cfe.bin /dev/mtd0;


The mtd commands come back with an error for some reason but it does flashes the cfe successfully.

4. Change the tftp server IP address to 192.168.0.66

5. Hold the reset/wps button pressed and turn off and on the router.
The firmware recovery kicks in and restores the stock firmware.

Hope it helps.

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