trouble-shooting a BPT audio intercom

[Ratten]

Hi,

I hope you can help me with some trouble-shooting advice regarding a BPT intercom system.

It comprises:

one AS C-200 receiver unit (in the hallway),
one A/200N controller unit (in the garage), and
one HA/200 audio module (at the gate).

It is wired exactly according to the diagram on page 2 of the document “http://www.smartrdistribution.com/userdata/files/bpt/system_200_audio_schematics.pdf”, (on this diagram, the YC/200UK is just an updated version of my AS C-200 receiver unit, with the same terminal numbers).

It has been working with no problems for some years, but it has now developed the following fault: the voice audio from the receiver unit is not heard at the entry panel. All other functions continue to work (the buzzer at the entry panel is heard at the receiver unit, as is voice audio).

I am unsure as to how to decide whether this is a problem with the microphone in the receiver unit, or a problem with the loudspeaker in the HA/200 audio module (or, indeed, a problem with the controller).

All of the connections are sound.

With the phone of the receiving unit on the hook, terminal 9 (audio from the receiver to terminal 9 in the A/200N) has a positive voltage of 11V.
With the phone off the hook, it has a positive voltage of 5.5 V.

With the phone of the receiving unit on the hook, terminal 12 (audio from the A/200N to the HA/200 audio module) has a positive voltage of 11 V.
With the phone off the hook, it has a positive voltage of 5.5 V.

Is there a way to troubleshoot this system so that I can decide which item(s) need replacing: the AS C-200 receiver unit, or the HA/200 audio module?

I have contacted BPT but they have said they cannot give technical advice to laypeople.

Thanks in advance,

ratten

 

[sparkymarka]

It’s probably the ha 200 . If no sound output at the entry panel ....open the ha200 desolder one of the speaker wires and check the speaker with a multimeter on ohms,think off top of my head they are 35ohms

 

[Ratten]

Ok, I'll try that after work tomorrow.

Thanks.

 

[sparkymarka]

OR .....does the panel ring ( you get audible ring at the entry panel when the button is pressed ) if not then it’s the speaker ...

 

[Ratten]

I don't think we have that in our system - there are only 2 buttons: the top one opens the gate, the bottom one (the auxiliary) doesn't do anything.

As far as I know the only audio that ever went from the receiving unit to the entry panel was voice audio (which is what has stopped working now).

 

[sparkymarka]

Post picture of entry panel outside ...when you press the button outside BPT panels give a ring tone when you press the call button

 

[Ratten]

I've just worked out what you meant - when you press the buzzer at the entry panel, can you hear it AT THE ENTRY PANEL itself? Pure genius! That just hadn't occurred to me at all.

Will try it when I get back from work.

 

[Ratten]

You nailed it, sparkymarka!

Not only is there no voice audio coming from the entry panel, but you can't hear the buzzer when the button is pressed. So it's very likely that the problem is at the entry panel side, not the receiver unit.

Do you still think I should measure the speaker impedance, or is the problem sufficiently narrowed down to the HA/200?

 

[Ratten]

The picture you requested: HA/200 inside a Targha entry panel.

 

[sparkymarka]

Worth checking the speaker if you have a multimeter, if not then new ha200

 

[Ratten]

Yeah, I checked the speaker resistance and it's reading "over the range", so I suppose it's blown.

I've seen a new HA/200 on the net for £40 (see picture), which I'm willing to buy, but I'm wondering whether this is the time to upgrade to a video intercom.... BUT, I would only do this if I could reuse the existing wiring (this goes under the drive, and there would be no way to pull new wiring through, and I'm not going to dig up the drive).

The info on the BPT website doesn't make it clear - do any of their video intercom systems work with four wires? (Or, for that matter, video intercom systems from other companies)?

 

[sparkymarka]

Normally you use a coax or a twisted pair for video , so it depends on what cable has been run

 

[Ratten]

It's just 6 wire cable with no shielding - not coax, not twisted pair.
No matter - I'll stick with the audio only. Is £40 about right for a new HA/200?

 

[sparkymarka]

 

[Ratten]

You're a star, sparkymarka.

Thanks very much for your help.