I have recently ran into a problem with a brand new ASUS Z170 motherboard. It just doesn't POST. I've went through a big amount of advices online and none worked. I've went down to basic motherboard-CPU-PSU-RAM-monitor build and yet nothing shows on the monitor.
My build is: ASUS Z170 motherboard Intel Core i5-6400 CPU Zalman 600W PSU Kingston HyperX DDR4 16gb RAM x2
Previously there ware also GeForce GTX970 video card and two old HDDs but I've removed them during debugging the issue.
The LEDs are showing that the motherboard is in normal/standby mode. Monitor behaves like my PC is in sleeping mode (it tries to get signal on HDMI but then switches to standby.
Frankly, I have no speaker to get beep code.
I had exactly the same problem before on my old PC. After working on this for a while I switched to new hardware (listed above). The only thing that remained from old build are the HDDs. At first my new motherboard and all other hardware worked well aside from Windows hanging during boot due to new hardware and old HDDs. At the point when I wanted to reinstall Windows and switched the HDDs between SATA channels - the PC just stopped working and wouldn't POST.