First unplug the machine and remove the battery. Press and hold the power button for 10 seconds then replace the power and see if it will start. This resets the power. Look in the battery compartment and give us the last three figures of your serial number please. Also try replacing your old RAM and see if the machine will start. Next try start then quickly hold down the P, R, Command and Option keys and wait for it to tone three times, This resets the PRAM.