Linksys 1200AC issue

Installing and Using OpenWrt
1

Hello!
I am new to the forum, and im sorry if this topic isnt meant here, it has been a while back since i installed OpenWRT on my Linksys 1200AC v2, i downloaded a build for the router from repository and installed it, the process was smooth, but after i tried to setup wifi i noticed i could only setup the 2.4ghz wifi and 5ghz was greyed out i tought something went wrong with instalation and i just left the router in the closet for a year, this week i went and reinstalled the original firmware from Linksys on the router, aggain the process went smoot and i can setup the names of the wifi but i only see the name of the suposed 5Ghz wifi and that if i place the phone next to router and even then i bearly get 50% signal, after i sucesfully connect to the 5gh (name is the one i set and even phone says its 5ghz) the only light on the router that blinks is 2.4 ghz.
I only want to ask what went wrong here is it possible that open wrt managed to physically corupt something, was it a coincidence and bad timing or is there a simple problem that im not suited to fix myself.

ps. before i installed open wrt the wifi networks worked without issues and i can't provede more details as i cant remember what version i used or where i got it from.
This post is more about seeking knowledge than fixing an issue. Thank you for any info that could be provided.

2

Doubtful, going on you flashed it back to OEM and you have a terrible signal I'd turn it off and open it to look if some antennas cable loose.

They would look like this.

c2eb4034f9663e89-3727554370
c2eb4034f9663e89-37275543701600×1600 122 KB

And ensure the normaal antennas are tight too.

If the ends did become unplugged, insert them and place a piece of electrical tape over them.

3

First, it's highly unlikely that OpenWrt corrupted your install. It helps if we know what version you currently have on the router:

Please connect to your WRT12AC OpenWrt device using ssh and copy the output of the following commands and post it here using the "Preformatted text </> " button:
grafik

ubus call system board
4

I checked and even tried connecting different antenaes with same connector that i had lying around and there is no difference but like i said this is probably a hardware issue, when i connect to 5gh the 2.4ghz light is blinking like crazy, the 2.4ghz isnt even visible and i tried several devices old and new im certain there is a failiure in the wierless hardware onboard i guess it was just a weird timing that it died.