I have 2 Archer C7's I'm trying to flash via tftp to return them to factory image. They formerly had OpenWRT on them, configured in AP mode to get an IP via DHCP, so I just defaulted to TFTP flash to quickly get access to re-configure them. I see them receive the image through tcpdump, however, the LAN-side interface never comes back up after receiving the factory image. I've tried every US version of the official tp-link firmware, also the most recent stable openwrt factory image.
The serial numbers start with 2151 and 2159, according to this post is a Jan 2015 and Sep 2015 manufacture date. Not sure that it matters, but one looks for 192.168.1.66 and the other 192.168.0.66 for a tftp image (IIRC, thats due to the bootloader version).
Anyone else have these issues or any other suggestions for getting any workable image on them? I don't care to solder; at that point I'll call them a lost cause.
Thanks for responding, jeff. I'm switching to 192.168.0.x network and pinging for 192.168.0.1. The interface on the archer c7's doesn't come back up - all I see on tcpdump is ARP requests and network advertisements from my own network interface. The LEDs on the front flash, except for the power, star, and the wireless 5G icon (looks like a boot loop to me).
For firmware revisions before 3.14.1 (140929), the router looks for an IP address of 192.168.1.66 and a file named ArcherC7v2_tp_recovery.bin. Firmware 3.14.1 updates the bootloader to look for an IP address of 192.168.0.66 and a file named ArcherC7v3_tp_recovery.bin even on hardware v2 units, but may also load ArcherC7v2_tp_recovery.bin. Some v1.1 units may also look for ArcherC7v1_tp_recovery.bin. The model Archer C5 looks for the file ArcherC5v1_tp_recovery.bin.
$ ls -l /private/tftpboot/
lrwxr-xr-x 1 root wheel 61 Feb 21 09:39 ArcherC7v2_tp_recovery.bin -> lede-17.01.4-ar71xx-generic-archer-c7-v2-squashfs-factory.bin
-rw-r--r--@ 1 root wheel 16252928 Oct 18 2017 lede-17.01.4-ar71xx-generic-archer-c7-v2-squashfs-factory-us.bin
-rw-r--r--@ 1 root wheel 16252928 Oct 18 2017 lede-17.01.4-ar71xx-generic-archer-c7-v2-squashfs-factory.bin
These are my notes below. I'm not too sure about "hold reset until TFTP completes", but might have to hold it until at least it starts. Pretty clearly I thought it important at the time!
@juppin - I think you are correct, I'm only able to get the device to take a close image match of whatever was flashed before onto the device (typically openwrt/lede).
I'm stuck on one last device that probably had an old lede/openwrt. I've tried as many builds as I can find - is there anyway to tell when that product id changes in the images (or change them myself ;)? I can get my soldering kit out, but I'll need some hardware to read it, then try to find an image with that pid, unless those can be changed in a build script.
@juppin - thanks so much. That thread is exactly what happened - in fact, I'm glad the openwrt/lede build you provided is still up because that flashed to my device.
Now it appears I have to write a new U-boot image to get any other image to take (or somehow modify the hw id) - using sysupgrade results in:
Invalid image, hardware ID mismatch, hw:ffffffff ffffffff image:c7000002 00000001.
Image check 'platform_check_image' failed.