I have a hp desktop that stopped working. When I turn it on I don't hear any beeps but I do hear the fans running and the light keeps flashing. Then when I turn on the monitor it says entering sleep mode and shuts off. No matter how many times I turn it on I get the same result. I've tried changing cables and the battery and no help. I've also tried taking out all four video cards and restarting like that and with then with just one and still no changes. What should I do? I'm I doing something wrong? I need step by step instructions for this computer smarts poor country boy. Please help! Thanks!