Computer beeps on sart up no display

On start-up red light on the motherboard come on , i hear one long beep then two short and then steady beeps very rapid. display does not come on , i can get the computer to work normally sometimes by turning off the power supply and disconnecting it from the power outlet.my computer is an E-MACHINES I RELOADED THE THE RESTAURATION CD'S NO LUCK TRIED THE RAMS INDEPENDENTLY STILL NO FIX
THANKS FOR YOUR RESPONSE