Satellite L55-B won´t start

[Ludek_]

My Satellite L55-B won´t start. It will start only when i plug AC. Only CAPSLOCK and NUMLOCK led lights and monitor is black. It can not start with power button. I can hear fun. I tried change RAM modul. Still nothing

 

[webworkings]

So it is on, but no screen? or is anything besides the fan on?