I have a a Linksys MX4200 v1 running OpenWrt 24.10.0. I used an Ethernet wire to connect to the lan port of the router.
I downloaded the 24.10.1 sysupgrade.bin from the firmware selector (openwrt-24.10.1-qualcommax-ipq807x-linksys_mx4200v1-squashfs-sysupgrade.bin) and then I tried using Luci (System > Flash new firmware image).
The device had flashing green lights which I took to mean it's doing the flashing, but the lights remained flashing for > 1 hour.
I then turned the device off (and the device predictably didn't function properly) and I had to perform 30/30/30 reset.
I was able to get the device to boot with 24.10.0 firmware, but when I tried the same procedures again (this time no longer checking the box that I wanted to keep the settings), I got the same problems (forever green flashing lights).
I understand that 30/30/30 reset has nothing to do with OpenWrt. However, as I understand it, the MX4200 has a dual firmware flash layout (according to the MX4200 OpenWrt page).
Therefore, before flashing, the sysupgrade, one partition has OpenWrt 24.10.0 (partition 1), while another partition has the Linksys stock firmware (partition 2). As I understand it, the sysupgrade will try to flash onto the partition 2. However, since it apparently failed, I had to remove power and when I replugged it back to the power, it wouldn't boot (because flashing failed). A 30/30/30 reset allowed me to toggle back to partition 1 and let me boot successfully to OpenWrt 24.10.0.
However, when I tried to flash sysupgrade a second time, it failed again. I am wondering what I am doing wrong.
Since the Linksys MX4200 has a dual firmware flash layout, it means that when I first installed the OpenWrt factory.bin using the stock firmware, the OpenWrt was flashed to partition 2, but the partition 1 still had the stock firmware.
When I was trying to use sysupgrade on OpenWrt, it was trying to flash to partition 1, but since partition 1 still had the stock firmware, sysupgrade did not work as it did not work on stock firmware.
What I had to do was to boot back into partition 2 (a 30/30/30 reset allowed toggling of the boot partition) that had OpenWrt, and then I had to ssh into it and flashed a OpenWrt factory.bin to partition 1 using the mtd command listed on the MX4200 OpenWrt page.
After the flashing was done and the router had rebooted, I then was able to use fw_setenv boot_part to set it to boot to partition 1 and it worked.
Basically, at this point, partition 1 has OpenWrt 24.10.1, while partition 2 has OpenWrt 24.10.0. Next time when I perform sysupgrade, it should work, and it will upgrade partition 2 from OpenWrt 24.10.0 to the newest version.