Do you hear only one beep when trying to boot the laptop? If you do, then probable it is a BIOS failure and the laptop needs a motherboard repair. Nevertheless, you can try something:
1. If your lappy is out of warranty, open it.
2. Take out the battery and the charger.
3. Take out the CMOS battery for 10 mins and after that plug it back.
4. Place back the charger and the battery.