Can you try to flash an older stock TP-Link firmware from the Web Interface, like this one:
If it works then try from step 2.
I assume that you've set your laptop IP to 192.168.0.66/255.255.255.0.
This test from localhost is almost a sure bet. Are you sure that your firewall is not blocking you on UDP 69 ?
The EU version of the C50v1 needs the following PR for flashing from stock firmware's web interface: https://github.com/lede-project/source/pull/1251
It might, I have to try to tftp from other PC to be sure
Its a pull request from july... I guess it was not merged (don't really know)... but I don't have experience compiling firmwares from sources, and don't want to brick my device. Thanks for the tip anyway 
I will watch for the PR to see if gets merged at some point into new versions
UPDATE: I found, for the moment, a solution for me. I am using the no-wifi old ASUS as an entry point (with entware installed for my stuff), and the Archer C50 for WIFI. I cannot afford bricking the almos new router. I will wait until the merge of the PR, or until other EU versions get the firmware downgraded and then updated to openwrt -> LEDE.
Thanks for your answers guys.
PR has been merged.
You should be able to install the snapshot “factory-eu.bin” image and from there install 17.01 via sysupgrade.bin if that’s what you ultimately want.
Just tryed that.
So I guess it is bricked 
I don't recommend to flash that snapshot to anyone else until it is tested
I will research what to do now, to recover wifi... of course, if I survive my wife and daugther trying to kill me when then awake.
Please, anyone with specific experience with the (eu) version of this router, and with the nexts steps, please come forward and report.
Thanks
PS I have the two files listed in this thread, one from mega, other from dropbox... here are the checksums:
547492efa11cf251c3a9fbf16eb4f517 ArcherC50V1_tp_recovery.bin
82f1331f68568696d1616dac115c0de2 ArcherC50v1_tp_recovery.bin
They are different (I don't know in which way), also one has capital V1 in the name, the other has lowercase v1, but that doesn't change md5... so there is a difference in the polish one, and the other listed here. May be that was the reason It wasn't working the TFTP method for me. I want to try that steps again and see what happens with the dropbox recovery version
To complicate more the options, if I strip de 512 bytes of the header in the Archer C50v1_0.9.1_1.0_up_boot(150325)_2015-03-25_14.03.35.bin using
dd if=Archer\ C50v1_0.9.1_1.0_up_boot\(150325\)_2015-03-25_14.03.35.bin of=rec.bin bs=512
the resulting file has this checksum: 4c0c5e8ffb59b8efb24cda050f7e96fa
Some hours ago, i broke one of the first laws of the universe (if it ain't broken, don't fix it) and have my instant karma. I was a little concerned about doing it or wait until other report, but decided to go along (has done a lot of firmware changes in a lot of devices, so I trusted my luck).
Now with the 3 checksums, I think that I have to wait a little for clarification. What I need to know exactly is:
Any help is very apreciated. Any recent success with the router, please share the details.
UPDATE:
My mistake... i did a wrong dd command, this one worked (missing skip=1)
dd if=Archer\ C50v1_0.9.1_1.0_up_boot(150325)_2015-03-25_14.03.35.bin of=rec.bin skip=1 bs=512
Now the resulting file has 82f1331f68568696d1616dac115c0de2 of checksum which is the same as the dropbox file... Im using that and the report.
UPDATE2:
I was stuck with resetting and waiting for TFTP... but I have a spark... what if the lowercase/capital letter v is important.
Changed from lowecas v1 to upper V1...repower with WPS and voilá... installed the original firmware...
Then made a sysupgrade to the openwrt and worked...
There was no GUI, but entered using ssh and used this procedure to perform the 3rd step @DjiPi mentioned:
Login as root via SSH on 192.168.1.1, then enter the following commands:
cd /tmp
wget http://http://downloads.openwrt.org/snapshots/trunk/XXX/xxx.abc
sysupgrade /tmp/xxx.abc
Now I have GUI... LuCi, and trying to get the latest version of LEDE... but there appears to be bigger than the space of the device
So I wont going to do that.
I believe that the morning bricking was probably for the same reason (a factory image bigger than the space on the device).
To recap, the tutorials to downgrade, go to openwrt.. and then to LEDE 17.01.1 work (probably would worked before if I realized the capital v letter in V1.
But using the lastest factory snapshot (which indeed can be flashed from web-ui) does kind of brick the device and forces you to do the 3 step procedure stated earlier in the thread.
I have risked a lot... now that Im saved and my wife and daughter still loves me, I will wait for another brave man to figure out how to upgrade to lastest version without having enough room).
I am new to LEDE and OpenWrt. I want to use LEDE because it is reported to have better WiFi on the C50 US V1.
I also would like to have an easy to use GUI like LuCi.
Does the LEDE firmware mentioned in DjiPi's first post include the LuCi GUI?
If not, is it possible to do this given the 8MB limitations of the C50 US V1?
CMIIW, but I think so, if we look at the config.seed used by the buildbot:
(...)
CONFIG_PACKAGE_luci=y
CONFIG_PACKAGE_luci-app-firewall=y
CONFIG_PACKAGE_luci-base=y
CONFIG_PACKAGE_luci-lib-ip=y
CONFIG_PACKAGE_luci-lib-jsonc=y
CONFIG_PACKAGE_luci-lib-nixio=y
CONFIG_PACKAGE_luci-mod-admin-full=y
CONFIG_PACKAGE_luci-proto-ipv6=y
CONFIG_PACKAGE_luci-proto-ppp=y
CONFIG_PACKAGE_luci-theme-bootstrap=y
(...)
That's great @DjiPi
Can anyone who has installed LEDE using one of these methods on a C50 confirm this?
Even if LuCI is not preinstalled: just install it, 8MB is sufficiently big for LuCI installation.
Well, I am not so brave as I could've been, but was having the same problem as you - where the image size was appearing to be bigger than the flash size, as pointed out here - and recently "solved" the problem...
So, for some reason, the LEDE sysupgrade image for the version 17.01.4 is much smaller than the previous ones, with a size of approximately 3,5MB (less than half o_O).
It was just a question of flashing the image from LuCI and I am now running the latest release os LEDE =D
I saw the solved issues, and tryed myself flashing 17.01.4 from gui. It was a success, but even when I checked keep settings, it doesn't, so it changed the gui IP without noticing me, and I waited in front of the "dont turn down the router" sign for a long time... until I started to suspect that the IP might be changed...
The update was applied, the settings where a mix from a new installation (and the old and configured one). All the mount options where lost, no swap, no extroot, etc. Tryed to restore a config backup made prior updating, but wasn't enough. After some config, it started to look as before (but updated). Many programs where running and had instances in init.d, but where not in the opkg database...so installed them, uninstalled afterwards (to clean the files) and in some cases, re-installed clean versions. But yes, it works now as expected, anyway I still wont recommend to a complete newbie to go thru all the steps from the original firmware to LEDE yet... until someone has a direct and hassle-free method working for the europe version of Archer C50.
Regarding the "keep settings" options - from Sysupgrading an existing LEDE device from the web admin GUI:
"Uncheck/clear the “Keep settings” checkbox! (more info regarding the "Keep settings" checkbox and it's rare use cases)."
To preserve your setting you have to backup the configuration and restore the backed up file after the upgrade...
I also would like to see a easier way to make the upgrade. I wonder if the new 17.01.4 images are suited for and upgrade from the stock firmware (but not enough to return to stock and try myself =P).
There seems to be a problem with the current factory images in snapshot, a fix is being worked on here: https://github.com/lede-project/source/pull/1467
Installed snapshot from 5 January 2018 on C50 V1 EU using factory-eu image ( because no release exist for it, I have to stick to snapshot, sniff), it works
Thanks for this firmware, I am looking forward for a lede 17.01.05 or 18.01.01 release to jump out of snapshots for the factory-eu
Thanks.
I got exactly the same as you, as far as I've got. But I'm going to describe it anyway, for emphasis:). Downloaded the snapshot eu factory bin (lede-17.01.4-ramips-mt7620-ArcherC50-squashfs-sysupgrade.bin) on 5 Jan, plucked up the courage to upgrade today using the TP-Link web interface; the upgrade was accepted and on reboot the device stuck cycling the LEDs through power/internet (amber)/all.
I thought that was it (I'm not going to be doing any soldering, that's for sure), especially after trying the TFTP method and getting no result. Not entirely helped by my network cable not always being perfectly well seated.
I made the same error with the file name, trusting https://wiki.openwrt.org/toh/tp-link/archer-c50, which has the typo with the case of 'V'.
Eventually, with my cable seated correctly, I checked syslog (no systemctl on my laptop yet) and could see that the device was trying to fetch file ArcherC50V1_tp_recovery.bin. Surely the name I was already using, but what the heck, let's try renaming my TFTP file. Bingo. Device comes back up with solid green lights.
That's as far as I've got for now (after checking I could get back into the web interface). Time to take a breath before deciding whether to press on.
Can you point out the place with the typo so we can get it corrected?
Is there anything else that I could add to my TL;DR second post to help others in the same situation as you guys (@shellsroof and @cedcuc17), or anything in general that would have helped you figure out things faster/better?
EDIT: I've added a note on non Windows systems in my TL;DR and I've also modified the Wiki and annotated a comment on the only ambiguous place that I've found. Please inform me if that was the place you were talking about.
Yes, that was the problem with the text.
I'm not sure when I'm going to have another go at flashing my C50, but I'll take a closer look at this thread first and maybe report back afterwards.
I came back to this today, so I'll say what I found, although there's nothing new here, nothing really that's not in your TL;DR post.
My device is the EU variant, and it shipped with the EU 160411 firmware from http://www.tp-link.com/uk/download/Archer-C50_V1.html#Firmware
The comment at https://lede-project.org/toh/hwdata/tp-link/tp-link_archer_c50_v1 says "To install on EU hardware, download factory-eu.bin from snapshot and optionally downgrade to 17.01 via 17.01 sysupgrade.bin". I've tried this twice (different snapshots, I believe) on top of the TP-Link 160411 firmware, and both times it rendered the device unbootable.
The factory-eu.bin did flash via the TP-Link web interface after I first downgraded the TP-Link firmware to 150325. (I had done that via TFTP, for debricking purposes. I haven't tried dowgrading the TP-Link firmware via the TP-Link web interface; I don't know if the TP-Link web interface would allow that or not.)
I then downgraded to 17.01.4, so I dare say I missed the point in using the snapshot factory-eu.bin firmware at all...
Anyhow, I have LEDE running on the device now:).
I know what you mean about the courage. If you have a limited budget, and have just bought a new router to your house, it doesn't cause any good impression (to your daughter or wife) to brick it on the very first days.
