Hi, I ordered a new custom build from newegg. Got everything all put together, went to test it without peripherals and every fan and light was functioning fine. After powering it down, I attempted to plug my monitor, mouse, and keyboard in and it wouldn't turn on. Had a friend look at it and he believed everything was done correctly, but couldn't figure out the problem. We did a test on the power supply and the fan turned on so i assume that's not dead, and when turned on the motherboard has lights flashing by the I/O port. I'm stumped as to what the problem could be and any help would be greatly appreciated.