RouterBoard SXT 5ND does not boot

[800908]

hi
my sxt lite5 antenna is not booting.
after applying power to it just turn on the power led and three top signal led as you can see in picture below.
it does not beep or any things else.
all voltage present.
1.7v, 2.1v, 3.3v, 5v.
caps around ICs are not shorted.
what the problem do you think?
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[800908]

as I searched the internet the bios is corrupted and need to be replace.
but the problem is there is license in the bios chip that need to be restored.
how can do this without loosing license?