I attempted to search for my specific issue before posting this but didn't see it. I built a new system using the following major components:

ASRock Z270 Extreme 4

Intel Core i5-7600K Kaby Lake Quad-Core 3.8 GHz LGA 1151

EVGA GeForce GTX 1060 6GB SSC GAMING

G.SKILL Ripjaws V Series 8GB (2 x 4GB) 288-Pin DDR4 SDRAM DDR4 2400  (note: verified compatible for this board on G.Skill's QVL list)

SAMSUNG 850 EVO 2.5" 500GB

Seasonic FOCUS Plus Series SSR-850FX 850W

Cooler Master Hyper 212 EVO - CPU Cooler

Connected a standard USB keyboard and USB mouse and a 1080p monitor via HDMI cable to the graphics card. Upon the initial boot, UEFI came up no problem and all was well. I could navigate the menus and set the date and time but I didn't change anything else. I started the Windows 10 installation process via USB stick. The Windows installer got part way into the install and gave me a stop error indicating an issue with the "system". I didn't get a photo of the error as it auto-rebooted before I could get a snapshot. Upon subsequent reboot, no video. The lights came on but nothing on video. 

Keep in mind that I was in the UEFI with no issues initially which suggests that I had my auxiliary CPU cable connected (I do) and the processor and memory is working ok as I likely would not have gotten into the UEFI and able to start the Windows install if these components were malfunctioning.

Since that first time, I've tried the following (not necessarily in this order as I messed with it for hours):

-Removed the graphics card and connected DVI directly to on board video

-Swapped memory into A2 and B2 slots

-Used one memory stick and alternated memory sticks

-Reseated memory multiple times

-Tried a different matched pair of the same exact memory but 2x4GB instead of the original 2x8GB

-Cleared CMOS two separate times by shorting out the jumper and waiting the requisite time as stated in the manual.

-Attempted to update the BIOS to v 2.30 using Instant Flash from F6 option. Updated locked up at 52%. Reset the BIOS to factory and it took two attempts to get it fully installed back to 2.20 and the UEFI back and functional (albeit temporarily)

-Removed SSD drive and just tried to get into UEFI with no drive.

During all these steps, at times, I could get into the UEFI after making one of the changes listed above and was able to restart the Windows install a couple more times but each time, the install would stop error at different points during the install. Some times the board would repeatedly power cycle, starting up for a couple seconds, turn off for a couple of seconds, start up for a couple of seconds, turn off, etc... Other times the board would power up with the LED lights but no video would appear. Once it messed up, I couldn't get back into the UEFI unless I made some kind of change to the hardware (such as removing/adding a memory stick). Also, sometimes the CPU fan would just go full-on and other times it would regulate speed. This was on initial startup and not after the system had been running for awhile.

During the second successful bios factory reset, the system ran for a few hours without any of the restarting issues and with video the whole time.

So this board is just randomly acting weird and I am pretty sure my CPU and memory is good and properly installed or, as stated earlier, I would not likely have been able to even attempt a Windows install let-alone see and navigate the UEFI.

At this point, I have an RMA into NewEgg to replace the board but I was planning on giving this system, to my daughter for Christmas so if anyone has any other ideas that I can try, I'd appreciate it. Thanks!