MacBook Pro not turning on

I tried following on replacing the thermal compound on the heatsink but never reached that point cause my screwdriver wont fit on screw near the power cable. After I returned back everything, I pressed the power button but it does not work. I connected the charger and turned it on it work but when i shut it down and tried to turn it on using battery it does not work. I tried to use the left shift + command + option. Now it does not even turn on but it is still charging