iPhone 5 no power

Hi everyone, I have an iphone 5 which i tried to do a DIY housing replace i did all the correct steps. when i removed the screen the first thing i did is disconnected the battery cable from the motherboard before touching the other components so i cant of done something really bad to it .

I have connected everything together tried powering it nothing no sound/vibration even when i plug it to the wall charger or PC (PC dont detect anything either. I did disassemble everything and assemble it back together just to check if i missed anything out. but no luck.

Thanks you.