Scepter 24" LCD Sleep Mode Issues

When I turn on my computer my Scepter 24"LCD monitor will immediately turn to sleep mode. The little blue light is still on this is how I know it is just not dead. Every now and then I am able to turn off the monitor and then turn it back on and there wont be a problem for a few hours then it starts again. I have had some luck pressing the sleep mode button on the monitor a few times also but I am stumped and need some help. Thank you.