Check the system with the adapter only and the battery only and see if it powers on. Check if any of the leds come on atleast for a second or two before it goes off. Is the light on the adapter on when connected to the system? Check if the adapter light is on / flashing / goes off when connected to the system. Check with another adapter if possible. Remove the RAM modules and check if the system powers on. Remove the HDD cable and ODD and check if it works. Again, see if any leds come on atleast for a second or two. If there are no lights, then I would suspect the motherboard might have failed and probably requires replacement. If there is no warranty, we can help setup a paid service call depending on your region.
My inspiration 15 5000  power button is not working  it was on sleep mode and was on table  water spilled  in the table and pc got moist from down  
lap top power button not working