Laptop wont start... strange symptoms

I have a Compaq Presario V5000, it's about 4 years old, but well taken care of. Sunday it decided it wanted to give up on life, here are the symptoms: The fan runs. Constantly. As long as the battery is in or its plugged into the wall the fan is running. The only way to make it stop is to disconnect both power sources. The mute light is on. Just like the fan, its on as long as there is power. The laptop will not boot, no matter how long I press the power button it will not start. Before it gave up it was sitting on a sofa, powered off, but plugged in and charging. In the 4 years i've had it it has never had any issue overheating. Thanks in advance for all the help.