MORE INFO: Here is our current handset connections:  Our current handset requires a call and then the handset to be lifted before the door entry button works (not sure if this is a feature of the handset or the intercom system itself, but our neighbour in the next block up has a different (older) handset that doesn't require a call or to lift the handset before the door unlock button works).

I would strongly suggest you try to find the manual for the handset in order to understand if you can overcome the call-before-unlock issue. There may be a link you can add which will disable the call-before-unlock behaviour. Out of an abundance of caution, randomly connecting 12V to the wrong terminal could cause issues... I know the guy from the company that maintains our intercom system wasn't too enthused about having "normals" fiddling with the intercom wiring precisely because it could mean transformer power is accidentally shorted to the wrong terminal and result in an expensive repair to the entry panel. :man_shrugging: Unfortunately we don't know what the app suggested for the wiring for this handset as it's not online (and I don't plan on reinstalling my Ring Intercom just to find out!) - can you post the wiring screenshot from the app? I'm not suggesting you go ahead and fiddle with your wiring, but based on the reverse engineering of the A harness in [this post](https://community.ring.com/t/ring-intercom-neon-access-and-guidance-on-what-each-wire-does/165329?u=neilm-uk)  then maybe the following wiring is close to what you need (these are the same 4 A-wires used on my Came/BPT Sytem 200 "AGT A200K" handset - compatible with the [C200](https://intercomsrus.com/finder/#B)) A3 -> 1 Mic (Speech Out) A2 -> 2 Speaker (Speech In) A1 -> 3 0V A6-> 4 12V DC

UPDATE: I've had some time to play around, and I've come to some conclusions: 1. The below configuration doesn't work: A3 → 1 Mic (Speech Out) A2 → 2 Speaker (Speech In) A1 → 3 0V A6-> 4 12V DC. When performing the test in the app, ringing the buzzer from the main intercom doesn't register in the app. 2. After some trial and error, it seems that the below configuration allows the app to detect the buzzer being pressed, however "unlock door" doesnt unlock the door: A3 → 1 Mic (Speech Out) A2 → 2 Speaker (Speech In) A1 → 3 0V A6-> EXT SND+ or TR (EXT PRIV+ doesn't register a buzz). 3. Interestingly, when in the above configuration (A6 -> EXT SND+ or TR), when I press "unlock door" in the app, the handset "Privacy" button lights up green (as if it has received a call, not attempting to unlock the door). I have not yet had the chance to see what happens as the buzzer is pressed, as I am home alone and the handset is on the 2nd floor, but I will get some help tomorrow and find out. My suspicion is that perhaps the handset needs to be lifted before door access is granted...

From what I have figured, the device simply tries to short two terminals for unlocking. If you can figure out which two terminals on your system allow unlock by shorting then maybe there is a way.

Hi Dave, Thanks for the reply. I'm definitely interested in trying to figure this out. I have a multimeter, just lots of trial and error I suppose. There is a product called "Nuki Opener", similar to the Ring Intercom with some drawbacks (no option to talk to visitors for one I believe). I have found a post where someone is trying to figure this out too for me specific handset: https://developer.nuki.io/t/nuki-opener-handset-gdx-23121-ring-not-recognised/17269 It looks like there may be some soldering involved potentially, which I will try as a last resort if I need to. Any thoughts?