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My router is a TP-Link Archer C20 (US) V5. I installed OpenWRT on it successfully using these instructions (made sure to use the US firmware of course) and it was working fine. For some reason I decided to put a fresh copy of OpenWRT again (using the flash firmware option in OpenWRT and uploading the boot.bin file which was generated the same way as before) and that seemed to have bricked the router.

I tried fixing it following this video tutorial. The recovery filename was tp_recovery.bin (got it from TFTP log as shown in the video). When the router is powered on while holding the reset button, the Ethernet LED keeps blinking very fast and the TFTP log shows that the recovery file was requested (no such error like "file not found", so assuming it was correct). Then I let go of the reset button and wait. A bit later the blinking stops and the router restarts. However after the restart the fast blinking resumes and keeps going on (I waited more than 15 minutes I think).

I also tried 3 different firmware versions from TP-Link website (Archer C20(US)_V5_201214.zip, Archer C20(US)_V5_200526.zip, Archer C20(US)_V5_200915.zip), but none worked. How can I fix this now?

Edit: I don't think this router has JTAG either. However, if there are some other hacky solutions, I'm all ears. Better than throwing away working hardware.

Thanks.

CluelessNoob
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    Some routers have the ability built in to recover firmware. Shut down completely. Wait 5 minutes. Start and see if it starts. If not, there is probably not much you can do. – John Mar 29 '23 at 14:30
  • Found [this advice](https://community.tp-link.com/en/home/forum/topic/81462?page=1) on the official TP-Link forums. – Giacomo1968 Mar 29 '23 at 14:46
  • @John The router had been off the whole day, so I just plugged it in to test, nope, same thing (ethernet LED flashing). Thanks anyway. – CluelessNoob Mar 29 '23 at 14:53
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    @Giacomo1968 I came across that page before, I tried the Linux equivalent as shown in the video mentioned in the question (I'm not comfortable doing technical stuff on Windows, especially if that involves some random software from cnet). Thanks anyway. – CluelessNoob Mar 29 '23 at 14:53
  • I've done it on a PC with a bricked bios, but I wonder if an 'in place' chip programmer would work here - I THINK the one I have is called a CH341A – Journeyman Geek Mar 29 '23 at 15:02
  • @JourneymanGeek Maybe, but I don't have much idea about those. I might be able to follow along with instructions if they are not too complicated. If you find any detailed link describing how to use that to recover router chips (for not-so-experts, hehe) that would be awesome. Thanks. – CluelessNoob Mar 29 '23 at 15:06
  • Half the 'problem' with those things is the knowledge is super poorly documented and specialised. https://www.youtube.com/watch?v=fbt4OJXJdOc suggests its possible though, I wouldn't desolder/resolder the chip if I can use one of those (slightly fiddly) chips. – Journeyman Geek Mar 29 '23 at 15:10
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    Have you tried the advice at https://www.tp-link.com/us/support/faq/1482/? – DrMoishe Pippik Mar 29 '23 at 15:40
  • @JourneymanGeek Very interesting approach, but sadly kind of complicated for me. But this could certainly work for someone more experienced. Thanks for the info. – CluelessNoob Mar 29 '23 at 19:29
  • @DrMoishePippik Yes, tried those, didn't work. All of the tries seem to end up with the good old Ethernet LED flashing. Thanks anyway. – CluelessNoob Mar 29 '23 at 19:30

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I have TP-Link Archer C20 (EU) V5 and Had the same exact problem and just managed to fix the problem (I still didn't do extensive tests but I managed to boot open-wrt) by using the tftp method to flash an open-wrt tp_recovery.bin from Linaro985's build by following this guide

steps:

  1. Go to Linaro985's build
  2. Downdload the file called "TPLinkArcherC20V5.zip"
  3. Extract the file called "tp_recovery.bin" from the zip archive
  4. Move the tp_recovery.bin to the rootbof the tftp server
  5. Set the server and ethernet configuration for tftp flashing
  6. Reset the router to start flashing
  7. Now the WPS? LED will flash and then power led will start flashing instead
  8. Wait for it to finish and then the power LED and LAN LED will be on
  9. Reconfugure you PC's network normally (If required)
  10. Open 192.168.1.1 from your browser
  11. congratulations, now you have a working router that runs the superior open-wrt

For TP official firmware: According to the The Guide I mentioned earlier the tp-link official firmware is tricky to flash using the tftp method and it recommended another method to flash it from within open-wrt

I also recommend using a firmware analysis tool called "binwalk" to get extra informations and insightbabout extra stuff (such as bootloader) that are included in different firmware package if you want better understanding about the issue

Mimo
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    Yes, that worked! Once Linaro1985's version was up and running, I even managed to flash the newer (I think) version - *openwrt-22.03.3-ramips-mt76x8-tplink_archer-c20-v5-squashfs-sysupgrade.bin* from OpenWRT website and it seems to be working (not extensively tested either, but looks good so far). Thanks! – CluelessNoob Apr 08 '23 at 01:07
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    Your welcome, btw which method did you use to flash "openwrt-22.03.3-ramips-mt76x8-tplink_archer-c20-v5-squashfs-sysupgrade.bin" ? – Mimo Apr 09 '23 at 03:09
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    Just normally uploaded the file in the flash firmware section of OpenWRT (Linaro1985's version) web UI. I think it showed a warning or something, but I force upgraded it anyway and seemed to work just fine. – CluelessNoob Apr 09 '23 at 21:07