MacBook refuses to boot after replacing logic board

Hi I have a 2015 Macbook 12” which I have replaced the logic board on after it would not longer boot. Just prior to this there were disturbances on the screen and then it would not boot. I have tried different chargers. Also have plugged in an adaptor to see if it would display on an external monitor but no luck. I notice that the white led on the logic board is on when the mac is plugged in to the charger but not on battery. Could this be a battery issue? Thanks Geoff