Home button flex repair by exchange U10

Hello,

I have an iPhone 7 with a non working touch id or button. Flex got hit by a plastic tool to open the lcd, and first large trace got damaged (From connector side). I already solder that trace and is ok, all others seens good without cuts, still phone don't recognize the touchid or button. How can i know if is a U10 problem or not?

I also like to ask where is the sync number, is also inside U10 or other chip?

For example, if i buy a home button and put the U10 from the original flex, touch id will work?