Kitz Forum

Broadband Related => ADSL Issues => Topic started by: toulouse on October 04, 2012, 11:09:34 AM

Title: Battery Contact Fault
Post by: toulouse on October 04, 2012, 11:09:34 AM
Hi there guys and gals,

I have been experiencing some problems with my O2 service since around 12 September. Prior to that date, I had been connected at around 15Mbps for the past six or seven weeks. However on this ill fated day, the router dropped the connection and came back at a little over 7Mbps. I contacted the O2 Support line, and described these events, and the initial response was that it was either a line problem or the router was in the process of failing. They sent me the new(ish) O2 Wireless Box V, but unfortunately this had no major positive effect. Then more recently, sometime over last weekend the line kept dropping and returning at reduced connection speeds, but would not stay up for more than a few minutes at a time. O2 support then started adjusting my SNR value (to 15, then 12), but this still doesn't seem to have resolved the problem. For example, during yesterday afternoon (heavy rain in the area), the line dropped at 14:57, returning at 16:19, and this pattern seems to have continued through most of the afternoon, finally dropping and not returning at around 18:00 last night. However, the O2 support guys have been pretty good, one of whom ran multiple WHOOSH tests yesterday, and discovered that there is what he described as a Battery Contact Fault on the line. BT Openreach are supposedly going to resolve that for me today.

The point of all this really, is that I wondered if someone (anyone) can explain what that fault actually is. I'm sure I've heard of others on here with similar problems in the past, but I still haven't worked out what it actually means,

.....so any information that either you can point me towards or which might help me understand what is going on would be most welcome.


TTFN


toulouse
Title: Re: Battery Contact Fault
Post by: kitz on October 04, 2012, 01:38:19 PM
When you report a fault, the isp can access some BT diagnostic tools that give a report on your line condition.   

Battery contact fault usually means that surplus voltage has been detected - possibly because your line coming in contact with another.  Theres several culprits such as worn cable, wet joint etc.

Have you done a quiet line test (Dial 17070 and select option 2), because this sounds like its more likely to be a fault with your phone line... which in turn is affecting your broadband.
Title: Re: Battery Contact Fault
Post by: toulouse on October 04, 2012, 01:54:35 PM
Thanks Kitz,

Yes, I have tried the QLT several times, and the phone sounds pretty damn quiet to me (not quite as quiet as your new PC, though !!!). During my chat with the O2 guy yesterday he told me that one of his colleagues had previously run various tests which had all come back clean, but he ran 2 WHOOSH tests yesterday and both of them reported the Battery Contact fault. I think I might have one of those devious intermittent fault type thingies. Perhaps I ought to wait and see what the Openreach guy achieves this afternoon, that is if he turns up or whatever he has to do.

TTFN

toulouse
Title: Re: Battery Contact Fault
Post by: kitz on October 04, 2012, 02:47:17 PM
>> I think I might have one of those devious intermittent fault type thingies.

The fact that it was worse yesterday when there was heavy rain, could be pointing that way.. particularly when water on the line is one of the common things that can trigger 'battery contact fault'.  See what Mr BTman has to say, other than that, it may be time to install Routerstats and see if that can show up anything.   Hopefully though they find the fault this afternoon :fingers:
Title: Re: Battery Contact Fault
Post by: burakkucat on October 04, 2012, 08:26:20 PM
There are two types of contact fault that a pair can experience -- (1) battery and (2) earth.

The first is where the normal -50 V DC has been detected where it should not be and the second is where an earth connection has been detected where it should not be. In both cases they are the result of a short-circuit to some other entity that has electrical conducting ability.

Water, wire trimmings, badly refitted joint cover, etc, can all contribute to a "contact fault" on a pair.
Title: Re: Battery Contact Fault
Post by: Black Sheep on October 04, 2012, 08:31:18 PM
It's extremely rare to be able to 'hear' a resistive battery contact fault, by utilising QLT on the phone handset. If there was a 'full contact' (IE- completely in contact with another line), then you would hear the other EU talking if you were both using your phones at the same time, but other than that ........... it will almost certainly still be quiet.

If it was a 'HR' then you would have a 'crackling' noise. If it was an 'Earth contact', you would hear a humming/buzzing noise.

Assuming you only have the one circuit entering your premises ??, then the engineer may not even visit you as the fault will be outside. If you have 2 or more circuits in the premises, there's a small chance it could be inside.
Title: Re: Battery Contact Fault
Post by: Black Sheep on October 04, 2012, 08:36:33 PM
There are two types of contact fault that a pair can experience -- (1) battery and (2) earth.

The first is where the normal -50 V DC has been detected where it should not be and the second is where an earth connection has been detected where it should not be. In both cases they are the result of a short-circuit to some other entity that has electrical conducting ability.

Water, wire trimmings, badly refitted joint cover, etc, can all contribute to a "contact fault" on a pair.

Just for clarity Mr Cat, 'full -50Vdc contact' faults, probably attribute to 5% of the total with regard to this type of fault. They are mainly resistive contact faults putting fault voltages anywhere from 1V to 50v on the line.
We use a wheatstone bridge circuit via our HHT's, to localise where the fault could lie. :)     
Title: Re: Battery Contact Fault
Post by: kitz on October 04, 2012, 09:12:56 PM
Thank you very much B'cat and BS for the much better explanations :)
Title: Re: Battery Contact Fault
Post by: burakkucat on October 04, 2012, 09:32:39 PM
Thank you, BS.   :drink:
Title: Re: Battery Contact Fault
Post by: Black Sheep on October 04, 2012, 09:52:16 PM
Worries ?? None.  ;D
Title: Re: Battery Contact Fault
Post by: toulouse on October 05, 2012, 10:12:26 AM
Ok guys, a quick update on the situation following BT Openreach visit yesterday afternoon.

The engineer, who coincidentally was the same one who installed my O2 line in February last year, did come and check everything for me. Some of you may remember a previous topic started by me concerning differences in 'loop loss' between my new O2 line and a line serviced at the time by Plusnet - this service is now non operational, although the NTE box is still present. As I live in a flat, there is a DP in a communal area, and after plugging a piece of test equipment (possible some kind of tone generator) into my NTE box, he took a look at the wiring inside the DP box. He immediately found a loose / disconnected wire which I think he referred to as HRDIS, and which he suspected could well be the source of my recent problems. Having sorted this out, he then went to the street cabinet, and found something else of concern, and from there onto the local exchange to do something else before coming back here to tidy everything up. He was here for a little over an hour and I did my best to provide adequate refreshments while he was here. He was a very nice guy, very helpful and informative, as I believe most BTO engineers are, at least in my experience.

During our conversation, we chatted about the forthcoming installation of FTTC at my local exchange (Weston-super-Mare), which according to him should be completed by the end of 2012. In his view, he said that based upon my current installation I might be fortunate enough to achieve up to around 36Mbps, possibly a little more - weehee !!!! He estimated that the distance to the street cabinet for my line is approximately 300 metres, although there is another closer cabinet which I estimate to be around 100 metres from my building. Both of these cabinets are quite old, and will be being replaced or whatever in the coming months.

A quick thank you to all those who have taken the time to respond to my request for information about 'Battery Contact Fault'. Foolishly I had been thinking that it related to a battery somewhere in the network, but I now know differently - so thanks.

I guess it makes sense to let my line run for a few days and just confirm that there are no more 'line bounces / speed reductions' before I approach O2 support to try and get my Target SNR reset to a more sensible level (currently at 15, I believe), and hopefully get back a large part of the speed that I have lost over this incident.

P.S. I have been monitoring the line with Routerstats since a couple of days after the initial problem of 12 September. It took me a while to set it up to work with the O2 Wireless Box V, but I got there eventually. I now have more stats and graphs that I can shake a stick at.

TTFN

toulouse
Title: Re: Battery Contact Fault
Post by: burakkucat on October 05, 2012, 07:50:27 PM
The engineer, who coincidentally was the same one who installed my O2 line in February last year, did come and check everything for me. Some of you may remember a previous topic started by me concerning differences in 'loop loss' between my new O2 line and a line serviced at the time by Plusnet - this service is now non operational, although the NTE box is still present.

Yes, indeed, I remember it well.

Quote
As I live in a flat, there is a DP in a communal area, and after plugging a piece of test equipment (possible some kind of tone generator)

Correct. An audio oscillator, usage of which allows the pair to be traced by monitoring for the distinctive tone.

Quote
he took a look at the wiring inside the DP box. He immediately found a loose / disconnected wire which I think he referred to as HRDIS,

HR == high restistance
DIS == disconnection

Quote
Having sorted this out, he then went to the street cabinet, and found something else of concern, and from there onto the local exchange to do something else before coming back here to tidy everything up. He was here for a little over an hour and I did my best to provide adequate refreshments while he was here.

A slice of cheesecake, perhaps?  ;)

Quote
He was a very nice guy, very helpful and informative, as I believe most BTO engineers are, at least in my experience.

That tallies with my experiences.  :)

So I think we can safely say that you have had a successful result!
Title: Re: Battery Contact Fault
Post by: toulouse on October 05, 2012, 08:03:03 PM
Miaow,

Yes, I think that may well be the case. The line has stayed up now without disconnecting at all for well over 24 hours, AND it's been hammering down with rain pretty much all day.

I'll wait until Monday and then contact O2 Support to see about getting the target SNR reduced a little and hopefully by the end of next week we'll have some sense of normality restored. Then after that I'm going to Blackpool for a few days - and then I'll really know what rain is !!!

TTFN

toulouse
Title: Re: Battery Contact Fault
Post by: Jonnyteg on October 05, 2012, 10:57:30 PM
Hope you got the problem sorted properly as some engineers just change pair with the source still not corrected a wet joint for example. 

Battery contacts are very common lines may work for years in this state with the end user still in service not aware, untill another fault occurs somewhere else like a full dis we come and fix the dis only to find battery on the line also  :no:,   A engineers nightmare  :lol:
Title: Re: Battery Contact Fault
Post by: toulouse on October 06, 2012, 10:13:30 AM
Hello Jonnyteg,

Yes, I think the engineer who called on Thursday was fairly thorough with his checking. However, I have this morning had a single 'line bounce' with an increase in sync speed from 8383 to 9787, but that could have been my ISP as they said they would be monitoring the line and may have adjusted the target SNR, which now seems to be around 12db, previously 15db, I think.

Is it possible that, as this problem may have been apparent for some time without affecting my service, that some automatic line monitoring system (or my ISP)  could have applied Interleaving to the line. I believe that this has occurred at some time since the initial problem on 12 September.
Title: Re: Battery Contact Fault
Post by: Black Sheep on October 06, 2012, 12:58:06 PM
Yes it is highly likely. Look forward to possibly 2 more "Bounces" (dropping you to 6dB SNR) which should result in you getting over 11Meg synch speeds.  :fingers:
Title: Re: Battery Contact Fault
Post by: toulouse on October 06, 2012, 01:24:53 PM
Thanks for that BlackSheep. Your mention of 11Meg ties in with what O2 Support have told me is the maximum that my line is capable of, despite the fact that I had previously been connected at well over 15M for 6-7 weeks prior to the incident on 12 September. In fact, I believe that the line has always connected at well over 11M since it was installed last year.

Perhaps its a YYGT
Title: Re: Battery Contact Fault
Post by: toulouse on October 09, 2012, 04:43:13 PM
Hope you got the problem sorted properly as some engineers just change pair with the source still not corrected a wet joint for example. 

Battery contacts are very common lines may work for years in this state with the end user still in service not aware, untill another fault occurs somewhere else like a full dis we come and fix the dis only to find battery on the line also  :no:,   A engineers nightmare  :lol:

Hi Jonnyteg,

....and thanks for showing some interest in this ongoing problem. Perhaps I ought to provide a little of the history behind this situation.

When I moved to my present address in 2007, and had the telephone line activated, I signed up with Plusnet as my ISP. From day 1 whilst using their service I had a SOLID 8Mbps connection, with 6db NM and around 29/30db attenuation. Over the course of time, when my local exchange was enabled for 21CN WBC, I was asked if I would like to transfer to that service, which I agreed to do. I had been advised via email from Plusnet that as a result of tests that they had supposedly carried out on my line, I could expect speeds of Upto 14Mbps on the WBC product. As it turned out, that was pretty far removed from the actual speeds that the line managed, I think the absolute max that I achieved was around 12Mbps, but I was reasonably happy with that. Then during 2010, the performance of the line just got worse and worse and I just got fed up playing ticket tennis with the support people at Plusnet, so......

.....I started looking around for a possible alternative to Plusnet, and as I am an O2 Mobile Phone customer, I decided to have them install a new line for me, which happened in February 2011. Naturally this was carried out by a  BT Openreach engineer, and rather than actually install a new line from the DP in my building, he chose to use what I think is referred to as a 'spare pair' in the existing cable from the DP. Again from day 1, this line performed flawlessly, initially at around 12Mbps, but gradually increasing over time, and most importantly, not dropping at all for weeks at a time. I chose, perhaps rather foolishly to run both the Plusnet and O2 lines in parallel just to compare the performance of each of them, and it was quite clear that there was some kind of problem somewhere with the Plusnet line. Then back in July or thereabouts after the umpteenth Plusnet support ticket being raised and getting nowhere with it, I made an executive decision to cancel both the Broadband & Phone line provided by them. For this I was instantly charged something over £25, and then the cheeky b*ggers billed me an additional £5 about a month after termination. Nobody could explain what that was for, and it took around 4-5 weeks to get that refunded - go figure !!!!!! Anyway, although the Plusnet service had been terminated, the actual NTE box is still present alongside the one for my new O2 line. Could this in any way be involved in my current issue ?

Anyhoooooo, jumping forward to 12 September, at some point during the afternoon (I was out at the time), the router appears to have dropped the line and reduced the sync speed from something in excess 15600kbps to 7000kbps. It had been connected at around 15634kbps for the previous 6 weeks or so, without interruption. I contacted O2 Support and explained the situation to them and was told that there was either a fault on the line or that the router was in the process of failing. They sent me the new O2 Wireless Box V (TG582n) which fortunately arrived the next day, but made not the slightest difference to the problem. They carried out some line tests, most of which apparently did not show anything up, and  I was contacted by a very helpful O2 Guru, who needless to say, I had to tell the whole story to again. He then ran a couple of WHOOSH tests which led to the diagnosis of the Battery Contact Fault for which I had a BT Openreach engineer last week. The BT engineer was ADAMANT that everything to do with the phone side was perfect, and he advised me that if I should have any further problems I should insist that my ISP arrange for a Broadband Specialist Engineer to get involved in resolving the issue.

...as to where we are at the moment, well I think there is something very seriously wrong somewhere, and I'll tell you why

At around 3:30am yesterday, i.e. Monday - the line dropped and was down for around 20 minutes I think, it then came back at the same sync rate as it had been at, and then stayed up until around 6:35am. From then on it was up and down, up and down, up and down......well you get the idea, I'm sure. Curiously, during this cycle of up / down, etc. it appeared that the line was trying to connect at something above 12Mbps, but in each case this lasted for only a few minutes at a time, and finally gave up the ghost with a sync speed of something short of 8Mbps. At around 10:00 am, I decided to try calling O2 Support, but the line was 'extra busy' at the time, so I guessed that maybe there were a few others also having problems. When I eventually did get through, I explained what had been happening since around 3:30, and the lady at the other end told me that they could see NO DISCONNECTS on my line - is that weird or what ?????? The router had literally been having a hissy fit since the early hours, but not according to O2. Anyway, it seems that standard first reaction is for them to run a 24hour test on the phone line, which according to what I was told earlier today has shown no disconnects or any other problems. Not surprising really, I suppose, as the fault that is present on my line is what might be called an intermittent one. So, at the present time they have reduced my target noise margin from 15 to 12, and that had the effect of increasing my sync rate from something like 7838 to 9537 where it has been since around 11:00 today.

More as I get it, dear readers, and of course you are welcome to add your thoughts on this situation,


TTFN


toulouse