Flat intercom not working for me, works for others in block.

[Ahleckz]

My intercom/buzzer entry system isn't working. When someone buzzes my flat number outside then my inside phone doesn't buzz. However, if they tell me they are outside then I can buzz them in.
When I pick the phone up normally, it's just high pitched squealing noises.

Would this be a fault with my phone, or with the outside panel? I'm leaning to think it's an internal problem because it seems to work for other people?

If it is internal, any recommended fixes that I could do myself before calling in the pros?

 

[Ahleckz]

Logically if there's no issue with anyone else's intercom then it's your unit at fault.

That's what I'm thinking but not really clued up on these things.

Is it wired or wireless version?

Usually with mains 220v intercom stepped down to 12-24v wired it's only a two wire connection for the intercom, plus additional feeds to the door entry release

Reckon it would be the best idea to take the unit apart and check for unconnected wires then? It's a wired one, and it's quite old.