iPhone 5 - Error 9 (Logic board replacement or U2 IC replacement?)

Hi All,

Two weeks ago I replaced my iPhone5's battery with a new one because its screen in lower left is bloating, making the home button unclickable. When I replaced it with a new one my phone got back to normal, but then just last tuesday I notice that my phone is bootlooping while charging. I went back to the repair shop where my phone's battery was replaced, they try to restore back my iPhone but they are getting Error 9 in iTunes. They already tried all possible things I've read here in apple community but nothing of them worked. They said that my U2 IC needs to be replaced, I also went to repair shops in Greenhills here in the Philippines but they said that possibly my iPhone 5's memory is defective because if the U2 IC is defective the phone will not open, so it is just either of the U2 IC or Memory. They tried heating my phones memory and tried to restore it back but then again Error 9 is returned by iTunes, so I conclueded that the board needed to be replaced.

Then just last night I talked to other technician again, they said that they'll try to replace my iPhone's U2 IC, if it works then my phone will be back to life but if it will not work it means I really needed to replace my iPhone's logic board.

Q:What do I really need to replace U2IC or Logic Board?

iPhone 5 32GB| Out of Warranty \ Defective