Why external microphone doesnt work on some Androids (like LG G5) I want to solve the problem with new Android phone (I use LG G5; and Motorola-Turbo2 too, but i dont care about it).

I use two kinds of microhpones (4 pin) :

=========== Wired =========



This mic actually has only 2 working wires (3rd an 4th rings connected to MIC board). Top 1st and 2nd rings are just empty. 

=========== Wireless =========



==== Problem ===

I can use WIRED mic perfectly with LG, but not with MOTOROLA (MOTOROLA cant see that as "mic", thus doesnt get any voice from it).

However, I tried to use Wireless microphone system with LG, it cant obtain voice (i have tried all ways), but MOTOROLA works with appliance perfectly.

As you know, the receiver outputs audio exactly on the same 3rd and 4th rings, but in addition, it adds some electrical power too, as a person is able to hear it softly in speakers (as opposed to WIRED microphone, which doesnt output anythig if something doesnt powers it)

Addition: I am a bit technician and tried to manually cut wires &amp;  connect lines with each other, to every possible combination, but in none of the case the LG worked with the applicance... 

p.s. I dont think that it matters whether 3rd or in 4th ring is "ground", because when I have exchanged 3rd and 4rd (ground &amp; microphone) wires, it didnt matter for phones. They are working the same way, only with "beloved" types...
tl:dr; Based on your observation that it works with Moto but not with LG, my guess is that it is due to conflicting TRRS standards -there are two standards. OMTP which is the older standard and CTIA/ AHJ which is the standard all newer Android devices are expected to follow

Details and solutions to overcome are listed 



From TS/TRS/TRRS/TRRRS: Combating the misconnection epidemic by Allan Tépper - ProVideo Coalition which talks of this problem on Android phones

There are two TRRS standards - OMTP and CTI / AHJ


OMTP is the older standard 


  The older OMTP wiring standard calls for Tip to be used for left audio, Ring 1 to be used for right audio, ring 2 to be used for microphone, and the sleeve to be used for ground. According to my research, this older OMTP standard is found in old Nokia (and also Lumia starting from the 2nd generation), old Samsung (2012 Chromebooks), old Sony Ericsson (2010 and 2011 Xperias), Sony (PlayStation Vita) and the OnePlus One I used to own before migrating to a Nexus 6 for use with Project Fi.



CTIA/AHJ is the newer standard, and is the standard to be followed for all Android devices, except where legal requirements mandate OMTP  ( see 3.5 mm Headset: Accessory Specification  |  Android Open Source Project)



  The newer CTIA/AHJ wiring standard reverses the last two mentioned, so it calls for Tip to be used for left audio, Ring 1 to be used for right audio, ring 2 to be used for ground, and the sleeve to be used for microphone. According to my research, this newer CTIA/AHJ wiring standard is used in products from Apple, HTC, latest Nokia, latest Samsung, Jolla, Sony (Dualshock 4), Microsoft (including Surface, Lumia, and XboxOne controller with chat adapter) and most Android phones.



From this, it appears that your devices are using different standards, though it's difficult to say which device is using which standard , but Moto being the older phone is probably using the older standard while LG is using newer standard.

Pictorial representation (see for discussion on more phones including Apple )



Problems in connection are around 
Ground  - since mic and ground are different in both standards. See also from SE.Electronics Hacking a TRRS to TRS adapter

Solutions


HAND TO KEY: Converting an OMTP/CTIA headphone to a standard TRS audio connection explains the steps in DIY project
Use TRRS to 3.5mm Stereo &amp; Microphone Adapter. Alternatively, 
OMTP/CTIA adapter can bridge the gap between a stereo headset and the wrong brand of smartphone ( bi-directional TRRS Standards Adapter for going between CTIA and OMTP or vice/versa)


Samples of the last two options are linked at the end of blog here


Using a TRRS to RCA adaptor as explained Add an audio input to Android
. A similar approach worked , though in a different case How do I use an external microphone with my Galaxy Nexus?


Before you invest  money, you can possibly verify by swapping the ground and mic , see this example from SE.Electronics



Edit: Post your edit today , saw This you tube video suggests that Wireless TRRS microphone adaptor worked to fix the wireless problem on LG V 10. I don't have any details on that or why it works but maybe worth giving it a shot considering, it's not expensive