Dell Latitude E7450 wont power on

Hi,i got this laptop and it fails to power on sometimes,if i keep it plugged in and NOT pressing the power button it will power on and boot to windows just fine but if i press the power button it spins the fan,HDD storage Blinks 1 time then fans stop spining and not powering on,what seems to be the problem?i have no battery in my laptop and thats it,keyboard and touchpad also wont work.

Update:when i plug the charger HDD LED blinks 1 time for one sec and if i press power button it blinks one time for shorter than a second