What do you think this does ... ?
I missed the link, thanks! How can I upgrade the device with OpenWRT firmware? Just flash the factory image from the web interface of the original firmware or is it more complicated?
Hi, you can try writing the image from the OEM web interface, but it didn't work for me.
I'll explain step by step how I did it to write the image.
You will need a POE injector, you can use a POE switch not connected to any network, use only the POE function.
Set on the computer that you will use to rewrite the firmware a fixed IPv4 address 192.168.1.5 with a network mask of 255.255.255.0 and connect it with a network cable to the Comfast router on the lan port, the one on the front.
On the front, remove the ornament that covers the holes for the fixing screws. You will see 3 smaller holes, besides the fixing ones. The one we are interested in is the one on the left, it is the reset button. press it and keep it pressed while from the poe injector with a network cable connect the Comfast router through the WAN port, the one on the back, keeping the reset button pressed for at least 10 seconds until the blue LED remains continuously lit. Now you can leave the reset button and open a browser, preferably Chrome or Edge, it didn't work for me with Mozilla, at the address 192.168.1.1. A special menu will appear where you can choose the image you want to write. The first time, when the router still has the OEM image, you need to write the file openwrt-ramips-mt7621-comfast_cf-e538ac-v2-squashfs-factory.bin from the zip archive.
If you followed all the steps correctly, the router will write the image and reboot with OpenWRT v24.10.4. Now you can set your computer again to obtain an IPv4 address automatically via DHCP and enjoy the unleashed functions offered by OpenWRT. I wish you good luck.
In the version I uploaded, Luci is not installed, but you can install it with the classic commands,
opkg update
opkg install luci
Once again, I recommend building your own version of OpenWRT, so you can choose which packages to include and take advantage of the compression offered by the build.
I hope I was helpful.
Thanks, I will try it tomorrow. Do all the basic function work (WAN and LAN port, wifi 2,4 Ghz and 5 Ghz, LED control)?
Yes, from what I've tested, everything works.
Hi, I tried your image, but it is not stable. After some time it just stops working and need to hard reset it to stock settings. Is there a way to go back to stock firmware or is this device now practically bricked (with not stable OpenWRT)?
Hi, sorry to hear this, mine, all 8, have been working very well for about 9 months now.
You can revert to the original firmware by downloading it from here and writing it to the router using the same method.
Hi, I have built a new OpenWrt image for you that includes Luci, you can download it from here. Same writing procedure.
Very important for performance, after installation, in Luci, go to Network > Firewall and change Flow offloading type from None to Hardware flow offloading.
Also instability can be caused by installing too many packages, so building your own image helps to avoid this problem, the build will fail if the image exceeds the device's memory.
Don't give up, the OEM version is still an older fork of OpenWrt, so it should work with newer versions. Mine does. Let me know if I can help you with anything else, I'll be happy to do so.
After the installation of OpenWRT image everything seemed fine, but after few reboots and/or network restarts it stopped working (i.e. no internet connection, device not getting IP address, no link indication on my PoE switch) regardless if I made any changes to the config or not. It seemed so random. But every time it happened, a hard reset was needed (holding reset for 10 seconds). Then I decided to flash original firmware (from the LuCi update menu) and it looks like this was the final nail in the coffin. It does not boot anymore (not in OpenWRT and not in original firmware), also the emergency boot menu (at 192.168.1.1) is not available anymore. After holding reset button for 10 seconds after connecting it to PoE injector, the blue LED stops blinking (is constant on), but the boot menu is not accessible anymore. I will try some additional things today, but pretty much I think the device will remain bricked. I already ordered the updated model 
Hi, sorry to hear that it is no longer working. Theoretically it is not defective, it can be accessed via serial connection, this requires a USB/serial converter, soldering skills, information and patience. You can get guidance here.
During the tests, I also encountered a problem at some point. The device seemed to be broken. In fact, when testing it disassembled, without the front cover, the first pcb board (there are two one above the other) had moved away from the one below and all the pins between them were no longer making contact. Maybe this happens to you too.
I managed to regain access to the U-boot recovery mode, from there I reflashed the stock firmware. Now it works again It was worth trying upgrading the device with pure OpenWRT, unfortunatelly it did not work as expected.