This question is about IP6 Backlight Driver Pads (C2/B2)

This is an iPhone 6 with no prior repair attempt that was last working a few days ago and sent in to me for touch issue repair. After the Meson Chip (U2402) replacement the screen not showing any image. On DC power supply, high current is consumed after prompt to boot, so I think the phone is turning on but not showing any display/image. My diagnostic thinking is the backlight driver were heat up when I was replacing the Meson Chip (U2402). So I take a further step to replaced the Backlight Chip (U1502), when I removing the chip from the board and suddenly the two pads are GONE ! The pads known as C2 and B2. I wonder what are these two pads responsible for ? Does this two pads is important for the phone to boot up normally ? ZXW Tools showing that these two pads are going under the Processor (U0201) and PMIC (U1202).

So what should I do next ?