NOW offical trunk version works include 5GHz, don't use this
Wiki page about this router.
https://openwrt.org/toh/tp-link/ac750
threads in https://forum.openwrt.org/viewtopic.php?id=52625
from April. copy-pasted from my rss feed cache.
https://pastebin.com/hVAq37iF
patched trunk version made by @franzflasch form forum.openwrt.org , doesn't support 5Ghz wifi
source:
https://github.com/franzflasch/openwrt/tree/archer-c2-support
patched LEDE-snapshot version made by me (imported @zaccareal's patch from here)(includes closed source mt7610 5Ghz wifi driver under /package/mediatek)
source:
https://github.com/orangepizza/openwrt-archer-c2-lede17.01
complied:
https://github.com/orangepizza/openwrt-archer-c2-lede17.01/releases
TFTP flash image for first install made by David Beinder
http://beinder.at/pub/c2_recovery.zip