联想g480主板维修图纸,联想g480g580

联想g480主板上有个裸露的芯片这个是北桥么?
联想g480 g400 y400 y/g580y470 v470 g510 y500 b460 g470主板
联想y410 y500 y400 y430p g480 g400 b470 y470 g500 g510主板
联想g480不触发维修
联想e47a e46l e46a 47l e47g k47 e49 g480 g470 z470 z370主板