(Solved) Archer C7 V2 Failsafe

Installing and Using OpenWrt
1

Had Lede running on the router and decided to use it as an extender/bridge and could only get one of the two radios to work at a time so while tooling with different configurations. The last time I had communication was setting it to a "client bridge". The ip was 192.168.3.1 and the dhcp server was OFF.
I have researched this in the forum and I don't see any tp-link Archer C7's successfully entering failsafe mode I was curious if there was anyone who had done it or if there was and alternative method. I can see both wireless radios and even connect to them but that's as far as it gets..

I have followed the documentation on trying to get the unit into Failsafe but no luck. When booting I can clearly see the blinking power led patterns and have tried to push a button but nothing. I have watched with a packet sniffer and at no time id there ever a packet that contains the text “Please press button now to enter failsafe”.

What am I missing? I don't think it's a brick but it is certainly unreachable.

2

If you can SSH into the router at 192.168.3.1, run the following commands...

firstboot

reboot

Otherwise, use this tutorial on the TP-Link forums to revert to stock firmware, and flash LEDE again...

http://forum.tp-link.com/showthread.php?81462-How-to-recovery-the-router-when-you-bricked-it1

Rename the stock firmware file archerC7v2_tp_recovery.bin

3

jwoods

Thanks for your help but it seems that every recovery method for this router depends on the reset button which, unless someone knows better, is purely decorative after flashing Lede. I was able to capture the right port with a packet sniffer and did see the message about "pushing a button" but again, decorative only.

Thanks again but at this point I am ready for the router to have an "electrical accident" and return it to the manufacturer (2 year warranty). Don't think I can return it right now with the radios broadcasting "Lede".

Any other suggestions. I appreciate them all!

4

tftp on C7V2 works for me, just did it a few weeks back.

Edit:
Sequence something like:

-hold reset button as power on
-all leds on (including WPS)
-leds off
-some leds on (no WPS)
-leds off
-few leds on but with WPS
-release reset button ~1-2 secs.
-switch led in use should indicate traffic(assuming your tftp server is ready)
5

Pressing the reset before turning the power on and holding it will always put the bootloader in TFTP recovery. LEDE never loads.

6

As mentioned above, when using the steps in the provided tutorial, the reset button works fine.

I have recovered C7 V2's many times using this process.

Works for other TP-Link models as well.

Common issues I see...

  1. TFTP server running on the attached computer does not have permissions through the firewall.

  2. Router not powered off first.

  3. Reset button not held in for at least 10 seconds after the router is powered on.

7

Okay, maybe I'm missing something so I will regurgitate my exact process.

Ethernet on laptop set to 192.168.0.66
Settings:
TFTP
Global
Only TFTP server is checked
TFTP

  • Configuration - Port 24
  • Security ? None/Standard - didn't matter

Advanced

  • Option renegotiation
  • Show progress bar
  • Translate Unix
  • Bind TFTP Server 192.168.0.66
    Firewall permissions set in/out
    With the router off and reset button held power button is pressed - reset is held throughout the entire boot process.
    Nothing?

Question - If the reset button is pressed and Lede is not supposed to load, why can I see the radio channels available?

I definitely appreciate the assistance!

8

iirc, if a tftp server is not detected within a timeout period the boot process continues. TftpPort=69?

9

Nothing should be changed in Settings. The defaults are fine.

Port should be 69

Security should be Standard

Bind TFTP Server should be unchecked

The router should be off. The TFTP Server interface should be selected to 192.168.0.66

The reset button should be pushed in at the same time the router power switch is turned on. Release the button after 10 seconds.

What firmware file did you rename to archerC7v2_tp_recovery.bin?

10

To all that responded... Thanks!

The link in the original post talked about port 24 not 69 and also gave directions on "binding" the ip. After reading the last 2 posts I fixed it in 30 seconds.

Thank you again!

11

Glad you got it fixed.

12

Just to add to this, because even with this post and the directions for using TFTP to upload firmware (https://openwrt.org/docs/guide-user/installation/generic.flashing.tftp)are so general that they are cluttered with extraneous information that perhaps is interesting, but not helpful in specific cases, I thought I'd post the solution I found, after several hours, which, admittedly is not too much different than the solution referenced in this post, but however does omit extraneous details.

It'd be great to be able to add this to the page for the router I was using (that is almost identical to the Archer C7) https://openwrt.org/toh/tp-link/archer_a7_v5.

Anyways, the clearest and most straight forward directions were actually here (https://wiki.dd-wrt.com/wiki/index.php/TP_Link_Archer_A7v5). Two key differences were to use Tftp32, not Tfpd64, and to use an older version of TP-Link firmware.

Directions are pasted below in case the dd-wrt link changes:

: This is still a work in progress in terms of clarity. The files below ARE ONLY FOR THE A7v5.

Download this recovery firmware file (DO NOT CHANGE THIS FILENAME)

THE FOLLOWING SHOULD BE UNIVERSAL FOR ALL TP-LINK ROUTERS: NIC must be statically set to 192.168.0.66 and subnet 255.255.255.0 (no other settings in win7/win10 necessary) Router/host/A7v5 will be sitting at 192.168.0.86 port 69 (The router will do this by itself).

Run TFTP SERVER (NOT CLIENT MODE) locally on the 192.168.0.66 PC NIC or Laptop NIC (NOT WIFI) using Tftp32 (it appears that tftpd64 has issues) Make sure to allow your TFTP program in the firewall rules for both private and public networks or you'll never push the file to the router due to the firewall blocking your TFTP program!

Make sure the tftp SERVER program has the right folder/directory chosen; which also has the recovery firmware file saved in that folder ahead of time before you start the process below. It's ok to have the tftp server program running and waiting for you to do the next steps.

Power off the router. Push in, and hold the reset button, power back on the router, while still holding in the reset button. If all goes as planned you will see a progress bar flash pretty quickly as the recovery bin file is pushed to the router. This happens within 6-8 seconds of powering back on the router with the reset button held in. If you have the TFTP server running the right way, the file should be pushed to the router right when the WPS led on the right side lights up (or actually a few seconds before). You can let go of the reset button when you see the progress bar on your TFTP server program move or once the WPS light turns on the router. The power LED will start blinking once it starts copying and upgrading back to stock. Sit back and wait 3-5 minutes as the router does its thing and Viola, you should be back on an early April 2019 stock build. You'll know you're back on stock build when the two Wi-Fi lights turn solid green. At that point you can go and reset your NIC card to obtain the ip automatically and resume restoring your settings in the stock TP-Link firmware.

The above revert file link will allow you to go back to dd-wrt if you want in the future. I don't know if future builds from TP-Link will lock out upgrading to dd-wrt, and/or, the possibility to not roll back to an older stock build. So be very careful in updating to new stock tp-link builds.

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