Reading the situation
The door opener, outdoor post, indoor post, relay and power supply form a circuit; the microphone, speaker, wiring and placement form the audio chain. A reset of the app usually does not solve an electrical or acoustic cause.
advice
Intercom: investigating door opener and sound problems
An intercom can provide a good image while the door opener does not respond or a conversation is muffled. Those functions use different parts in some ways and therefore must be investigated separately.
First evaluate
Note the exact behavior: does not work when opening anywhere or only on one device, does the humming continue or only during talking, and what changes when ringing? Check model specifications, power supply, cable routing, relay setting, and the type of door hardware without having to connect any voltages by touch.
The correct next step
Isolate one layer at a time and change only what the measurement or test indicates. During sound testing, check placement, sealing, cables, and possible feedback; during opening, check contact duration, power supply, locking function, and safe mechanical output.
Check after the change
Test the conversation in both directions, open from any authorized device and observe the behavior under normal doorbell ringing. Record the cause, change, and any limitation so that a follow-up technician does not start a general reset again.
Frequently asked questions
Why does video work when the door is not opening?
The door opener has its own relay, power and door hardware chain in addition to the image and conversation.
Does the echo always come from a faulty external post?
No. Placement, volume, sealing, cable and feedback can all affect it.