This page describes how to get the Intel 3165 wireless card working on Ubuntu 15.04 on the Intel NUC 5CPYH.
To fix this problem:
Check the linux kernel you are using $ uname -r Even if you've installed Ubuntu 15.04, it's still using the 3.19 Kernel.
Right now, Intel is only supporting the 3165 hardware with firmware for 4.1+. So you need to upgrade to 4.1. It's easiest by using wget to get the right version for your hardware, and for whatever kernel you want to use. I wanted the most recent stable release. Use wget to get them. (I can't post the links on how to do this because the forum won't let me until I have a reputation established.)
Download the appropriate firmware for the 3165: https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi#firmware
You'll see it's called "iwlwifi-7265-ucode-22.214.171.124.tgz" Unpack it, and then navigate into the unpacked directory.
MOST IMPORTANT: THIS SOLVES THE ISSUE: Look inside the unpacked directory, and rename the two ucode files to match those that Ubuntu is looking for (at least in my case):
- iwlwifi-7265D-13.ucode renamed to iwlwifi-3165-9.ucode
- iwlwifi-7265-13.ucode renamed to iwlwifi-3165-13.ucode
- Move those two renamed files to /lib/firmware
BAM! You're done.