Laptop cooling fan full speed working

i have a vaio f115 fm and i have a same problem but one time my battery is dead and need recharge my laptop went off after that and for next use i forget to charge it and just press the power button to tunr it on but the green light on the power button was flashing i plugged charger and press power button again but it dosent turn on and i wait for 20 min .after that i take off the battery and then put it back and after that every time that i atart my laptop my cooling fan working in full speed ( i think maybe i should do the battery job again then i do that and take off battery for the all day long and out it back in but it dosent work ) what shuld i do plz help me i really concern about it ??!!!!!!!!!!!!