Lg g4 sudden dead

My G4 was suddenly dead at last couple hours , just received a call after that the device won't turn on whatever i've done . Swapped with backup battery doesn't work either . I think the motherboard is defected , does someone know how much it cost for the motherboard ?

P/S : I owned the device with start S/N 505K .. & NO MORE LG PHONE !!!!!!!!!!!

Download from this link