Laptop not starting up

Hello,

I am having dell inspiron laptop which is about four years old, last day i kept it on sleep mode and when i tried to wake it up, its not starting. Its having a 'bad' baterry ,so i pluged it to a power source and tried to start it, but the charging notification light went off after 2 seconds. when i press the power switch on my laptop its actually getting onn but stays idle with the power notification light on without booting. i plugged my laptop without baterry but the result was same, so please help me sir.