I have Asus RT-AC51U Router, with Mediateck Ralink MT7620N
I bought this to use as a development board.
The flash chip is KH25L12835FMI-10G 128Mb 16pin 2.7/3.6V
I have removed it and read and saved original flash content.
I tried to delete it but do not clear, I assume is protected.
Then I took a WindBond W25Q128JV 128Mb 8pin 2.7/3.8V
I have build OpenWrt using RT-AC51U preset.
But not boot.
Digital Signal on chip flash run constantly, as if the CPU does not find the right boot.