Z170N-WiFi - USB boot hangs - AAGGHH

Followed ammulder's guide to the T. On El Capitan and Sierra.

I cannot get my build to install OS X. Regardless of OS version - Hangs after 1 microbar of progress of booting after clover screen.

System is:
Z170N-WIWFI, I7-6700K, 16GB Ballistix, 1TB SSD...

Bios ver if F7

HELP!
Terry