Where is the 1520 WiFi Antenna?

[nitzero]

So I'm recovering a broken 1520, both screen and back cover and I'm wondering what makes the WiFi signal works which is not the same as the modem Antenna because 3G/4G signal works fine however WiFi/Bluetooth signal is nearly non existent.

I'm wondering if the back cover needs to be properly pushed against the connectors on the upper right corner, if that's the case, I might be at loss here because the case is somewhat damaged and I purchased a chinese one which doesn't quite fit on that part. Maybe if I plug an antenna cable between those two connectors on the upper side? I'm just not sure if that would solve my problem.

Purchased two original back covers and they seem to have suffered from some kind of dryness that made the plastic too brittle, I even tried to use some heat to snap the cover in place but it broke anyways.

 

[MDK22]

Search 'Lumia 1520 Service Manual' ...
I'm looking at it now (on my phone), this includes schematics, full teardown, etc

 

[nitzero]

I am having some inconsistency with signal, whenever I plug the gray wire, the signal gets really good on the local network but fails to find any other distant network, when I plug the black wire the signal drops to 4/5 right besides the router and 2/5 to 5Ghz.

I thought it needed some extra connection to the case but maybe I just got a bad antenna? The cables and connectors are in good condition.

 

[gordonfink]

I know it plugs into both boards, but I am not sure where the actual antenna is. The service manual identifies an IHF Antenna under the USB board, but I am not sure what that actually is.