I have a problem with MQ-PRO H616. It doesn’t work right out of the box. It acts like it’s not booting. The second copy, after inserting the same SD card, starts flashing with a blue LED and boots. In this one, only green lights up when power is connected. Has anyone had a similar problem? Is it possible to reload the firmware containing the bootloader? Is there u-boot in this board?

Same problem!!! I have 10pcs like this. do you now fix it?

I use debian release that works correctly.
And dts file you can find here:,
In doc you can find how to transfer it to dtc.