My inspiron laptop won't turn on but power LED lights up and stays for a few seconds

Please help me. The power light turns on but the laptop is still not turning on. I have also tried solutions from dell replies on forums but still got nothing. Can you please help me with this? Ive also noticed few days ago, my laptop beeps when I try to turn it on but turns on after several beeps.  I got single beep for every 5 seconds I think