My monitor first started to go dark after a few minutes and then come back on for about half a day. Then it went dark completely and if I turn the power off on the monitor if comes on for one second then goes dark and stays dark. I can repeat this and it does it over and over flashes for one second then goes dark. I have also tried a different monitor and cable and that one does the exact same thing. Comes on for one second then goes dark. . An ideas on what is going on?