Intermittent dial-tone and broadband

[dk1uk]

Hi - hoping someone can help me.

I've noticed today that I have only an intermittent dial tone on my BT landline and an intermittent BT broadband connection.

I called BT who have said that they think the issue is in my house as they can't find a fault on their network. However, the engineer isn't coming for a week - the bad weather has caused a back-log. So, I'm going to need to at least try to work out what's gone wrong myself.

It was fine yesterday, nothing has changed, so I'm at a loss as to what's happened. I am starting to draw a conclusion that it must be BT's problem and nothing in my house. The cable from the telegraph pole to my house is still there, we haven't had any strong winds etc. that would cause any damage.

My equipment is plugged into the master socket and I've tried every combination of unplugging/plugging in the BT homehub, then just the landline, changing the ADSL filter etc.

When I don't have a normal dial tone, there's either a lot of cracking or a continuous sound - as if the connection has been cut. The phone also rings occasionally (one or two rings, when I answer, no-one there).

Something has obviously gone wrong - does anyone have any ideas, or shall I just sit tight and wait for the engineer?

Many thanks.

 

[dk1uk]

And also, if I dial my land line from my mobile, I get an engaged tone?! (no one is using the phone, it's dead).

 

[chaindaisy]

Greetings DK,

From an observer's point of view, it would appear that you have done everything you possibly can to eliminate a fault inside the property. If you have access to a multimeter, and also acccess to the incoming. Place the meter across terminals 2 and 5 after disconnecting the house terminals at that incoming box. You should have about, emphasis on about, 100 volts DC when the phone is ringing in, 0 volts DC when there is a conversation, and 50 volts DC when no one is ringing in or out. So, in a nutshell, look for 50 volts DC on terminals 2 and 5. There are a few ways to achieve this, and by all accounts my method is wrong according to the site BT engineers, and I don't dare argue with them, however, my test as outlined as never failed me yet. It would appear that the fault is outside, particularly with the 'crackling'.

Take care,

CD

 

[dk1uk]

Thanks - I do have a multimeter but not access to the incoming - up on the side of the house - other side a steep ditch and I don't have a long enough ladder.

I can only imagine that BT's line test isn't telling the whole picture.

Thanks again.

 

[Stevoon]

Crackling is often water in the incomming cabling, especially if the drop wire to the house is the old "figure 8" grey cable. I have seen it many times where the BT Line Test fails to find the fault and you get the whole "if we send an engineer and it turns out to be on your equipment it will be chargable etc" but often it is because either the fault gives a resistance similar to the complete loop circuit or I suspect the phone jockeys are paid to not accept faults.

 

[chaindaisy]

I was expecting an expert to come along Stevoon, glad you have. Your the first one not to knock my method of testing incoming though. Four of the guys in our firm are ex bt, and they make the finest installers in my opinion.

Take care,

CD

 

[Stevoon]

I do the -50v incomming check, and if i don't have a meter handy it's even known for me to ring the number in question and short the pair to answer it then tap them together to listen for "clicks" to make sure I have the correct pair. I'm sure thats not in the BT test guide!

 

[chaindaisy]

Hi Stevoon,

That's brilliant, do you mind if I use it ? Won't say where I got it from. At one time there were handsets with a few buttons, going back a bit though, they were very handy for checking the line to the ARC, (just strap across the line) and also very handy to phone home on that same line to tell the missus I'd be late for dinner (rarely paid for a phone call in those days)

CD.

 

[Stevoon]

Yes that's fine by me. I'm not BT or anything like that, just the Telephone System Engineer where I work so most of my tests etc have to avoid the expensive kit and make do with what we have to hand. I did explain my theory for testing I had the correct pair to a BT engineer who looked sceptical until I demonstrated it to him!

 

[chaindaisy]

You're one in a million, Stevoon.

Look after yourself mate,

CD

 

[dmiller]

You should have about, emphasis on about, 100 volts DC when the phone is ringing in, 0 volts DC when there is a conversation, and 50 volts DC when no one is ringing in or out. So, in a nutshell, look for 50 volts DC on terminals 2 and 5.

You have two legs into the back of the master socket, A and B. With respect to earth you should see in normal line conditions (ie on hook) 48v DC on B and 4v DV on A. In ringing conditions you should see 75V AC on either leg. (Thats what makes your phone ring) then once off the hook 48v and 4v DC as before.

Intermittent crackly phone lines with no dial tone are:
- Water in a connection.
- Damaged drop cable (the cable coming into your house).
- Damaged pair back to exchange.
- Dodgy extension wiring.

You cant really check any of the first three and the fourth is the one openreach will charge for attending.

The best test you can do is pop the face plate of the master socket and remove all your extension wiring and just connect your micro filter and phone / modem to the test socket in the master socket. If the fault is still there BT need to fix. If its gone then your extension wiring is causing it. even if you plug everything into the master socket already and don’t use the extensions a previous owner may have wired something daft. Also house alarm installers can also run extensions you don’t know about.

Also be careful stripping and shorting wires together - it will work but if something has gone very wrong somewhere you don’t what the voltage on those cables will be. Its also possible to damage exchange equipment that way.

Hope that helps,

David.

 

[kbdiy]

Firstly have you eliminated the phone from the equation - ie have you used a known good phone to test? The reason I ask is that you say incoming calls get busy tone so just wanted to check you have eliminated that from the problem.
Otherwise it is much as previously suggested. You need to isolate all internal wiring and test only at the master socket. What do you get when ringing in with no phone or internal wiring connected? If still busy tone then without doubt it is a BT fault. Any noise/interference on the line would cause the broadband problems as well. The 'false ringing' that you have experienced also suggests an external fault. Water in a joint or cable is the most likely cause (especially given the recent weather!)
Incidentally when testing with a multimeter you get 48vDC across the incoming pair (-48vDC on the 'B' leg and 0vDC on the 'A' leg), with 75vAC ringing. Testing with reference to earth is fine if you know the earth is a good quality otherwise it could lead to erroneous readings.