Z170m Extreme 4 will not POST; RMA?

I?�ve been fighting a new build for the last several days and have run out of ideas.

I?�m about ready to RMA this board, but thought I?�d come here for any final suggestions any of you might have. This is the first and only AsRock product I have ever owned.

The new hardware is:

AsRock Z170M Extreme 4 motherboard, Intel i5-6600K CPU, a matching pair of 4 GB sticks of Hyper X DDR4 2666 RAM from the AsRock qualified vendor list.

Old hardware carried over from previous build that was working fine last Saturday:

Antec Solo II case, no video card, Crucial SSD for OS only, 3 spinning drives (WD and Samsung), Rosewill Silent Night 500 watt power supply, Samsung DVD burner, Microsoft wired keyboard, Microsoft wired optical mouse, Noctua NH-U12S cooler, Dell 23 inch flat panel monitor connected by DVI-D. It does not support HDMI.

Nothing at all in the PCIE slots. This is a simple, non-gaming PC.

Problem description:

It has NEVER posted. The case speaker has NEVER beeped. I get NO screen output. For a few hours, I did get the CPU fan to spin and I did get the hard drives to spin.

For the last 24 hours, I can?�t even get the fans to spin. No screen output and no signs of life.

I?�ve done all the troubleshooting steps I can think of, such as:

Pulling all parts out of the case and re-assembling on a tabletop on cardboard.

Reseating the CPU and CPU cooler.

Cleared CMOS by 2 different methods, including twice pulling the battery for 4 hours.

Trying each RAM stick individually into all 4 slots, one at a time.

Trying RAM pairs in the recommended A2 and B2 slots.

Using 2 different power supplies, using just 4 pins on the ATX 12 volt header and also using all 8 pins on the ATX 12 volt header.

None of the above steps has made any difference at all.

Does anyone have any final suggestions I can try in the next 24 hours?

If not, it goes back to Newegg and I choose another brand.