Long story short: the RX 480 crapped out after a few months of us (2 months maybe that) blue screen on boot then eventually just black screen. RMA'd the card and we recently just received the refurbished card that was claimed to be tested and working. Tried in two different systems but when the card is installed (fully plugged in) there is absolutely zero display, no post, can't get to BIOS, nothing. Tried a GTX 970 and both systems work properly.
We did clear drivers, BIOS is up to date, tried switch between UEFI mode and Legacy in BIOS when booting from integrated gpu, still nothing.
Did they really resend us another broken card after all this time and hassle?
(System this card is for)
Windows 10 64bit
MOBO: Gigabyte GA-B85M-HD3
CPU: Xeon 1231V3
PSU: Seasonic 520W 80+ Bronze
GPU: RX 480 4gb (6 pin)
It certainly looks like the replacement card is defective as well.
Unfortunately, it looks like you'll need to RMA it again.