Last week installed new XFX R9 280X video card.
New RAM, 4 x 4GB Kingston HyperX Beast 1600 MHz DDR3 PC3 non-ECC CL9 DIMM XMP.
New power supply, Ultra X4 Special Edition, 750w 80 Plus Bronze M.
Ever since, a random crash of the computer with the monitor going to black (still powered, but in standby), no mouse or keyboard will work,
a buzz in the speakers, and the hard drive stops, tho all fans keep running.
The only thing I can do is do a hard shut-down (hold the on/off for 7-8 seconds), then power it back up.
Can you help?