So a couple of weeks ago my monitor started going into sleep mode in the middle of use. After restarting it comes on fine. Pretty soon after that it always goes into sleep mode producing no video. I checked my mobo and power supply and find that both had semi fried. I sent both of them to be replaced and put the new components in. Same problem with no video signal. I also noticed that my keyboard gets no power and my onboard NIC has no lights. However the computer powers up fine with no beep or light codes. All fans and lights are working fine. What is the problem?