Thread: DSL drops connection during power cuts

Hi everyone,

I've a little problem with my dsl connection:

Everything works fine in general but when there's a power cut, my modem looses the dsl connection and doesn't manage to reconnect regardless that it is plugged on a UPS.

It just keep trying reconnecting without success.
And when the power comes back it reconnects.

It used to work fine but since a week or two it started acting weirdly.

I tried changing the modem, the UPS, the cables, the dsl splitter, the modem power supply.
Plus if there's power but I switch off the current in my house, the modem doesn't drop de connection.

I can't seem to find the problem and don't know who to ask.

Does anyone know what can I do to resolve my problem?

Thanks

I use APC Back up UPS. There are three sockets. But only two give back up and one is for surge protection. Please check your UPS and confirm all sockets
supports back up.

Mains power fails
Modem fails with UPS supply ( "hunting")
Mains On
Modem reconnects.


mention modem model/make
and details of Power adapter.
220V ac input
output 12V AC
or 12 V DC 1 amp etc

@engine: dude get a modem with inbuilt battery backup system,i am using innomedia MTA-6328-1Be2s from reliance in which there is a 8 cell battery pack(9.6v) which gives 6 hours of backup.

meetdilip: As power cuts are really frequent in my area I have a UPS for the full house (fans, lights,...). It worked liked this for maybe a year. It just stopped 1 or 2 weeks ago.


I have the classic UTstar WIFI from bsnl (dataone), but I tried a NETGEAR (I don't remember the model) same result.

essbebe: I, like you, though it could be related to my UPS, but I managed to get an other UPS and it acted the same way.
Plus if main power is there but I switch it off in my house (the main electrical breaker) then the house is power via the UPS it works fine. The modem power supply is a 220V/12VDC, and I also tried a different one without any luck.

@engine9

The modem power supply is a 220V/12VDC, and I also tried a different one without any luck.

Temp solution( may be permanent !)
Now see the PLUG going to the modem.
In the power adapter it will be marked
Inner +VE or outer +VE D.C
Observe the polarity.VERY IMPORTANT
Prepare another connecting cable of same type.
and connect Directly
One end to +ve and _ve terminal of battery 12V
and another to modem power point.

Feedback.
@jatinder911 replacement cost of modem ? > approx Rs 2000/=
suggestion above:
Expenditure less than Rs 25 to Rs 40
Material required;
Two pin Philips type plug ( matching modem Port 12V ) Rs 5/=
cable say Rs 10/=
two battery clips ( crocodile type )say about Rs 20/=

Originally Posted by engine9

As power cuts are really frequent in my area I have a UPS for the full house (fans, lights,...). It worked liked this for maybe a year. It just stopped 1 or 2 weeks ago.

I basically don't know much about the UPS batteries but i came to know about this fact as i had suffered a problem they told me as time passes and due to continous usage the no. of cycles gets increased of the Battery ............ i'm not sure as to this has any connection to your problem or not because the problem which i had suffered was that while in the condition of a power cut in my region i was switched to the battery mode but then the 2.1 speaker system started making a continous odd sound and they told me that this wasa happening due to same change in the battery cycles ........... maybe some frequency change ................. while this didn't use to happen while the battery was new ........... i have a APC back UPS ..........

Possible explanation :

Usually, if the power failure is , for a longer period
the terminal D.C voltage of the battery would have gone down.

Say you cannot use UPS , after 4 or 6 hours
with max load connected.

And when power is restored, Battery also gets charged, ( with built in Battery charger )at a fast rate/ or trickle rate.

This also places an additional load on the UPS, affecting other equipments connected to it.
( whether change over is direct to Mains by passing UPS circuitry> to be checked : via a relay)

eruptionjoojo: When the power comes from the UPS, I also have weird sound in the speakers.
The UPS doesn't seem to be the source of the problem as I changed it yesterday and I still have the same problem this morning.


essbebe: I rarely end without power as I have a 3KV UPS with 3 batteries. It can last 24h with the computer and modem on. The UPS and batteries are 1 year old.

I usually don't have so much load, a desktop computer, a modem, a fan so it shouldn't be too hard for the UPS. In worst cases, the modem would reboot but manage to reconnect, now it just looses the connection and keeps trying without success.

After a big surge, I had to change the UPS relay like 6 months ago, the UPS guy came yesterday to pick up my UPS and see if there are any loose contact
or anything else, but again, I gave me a UPS for the time being and I had the problem also with that one.

I'm gonna try with an extra small UPS just for the modem and see what it does.

The more I think about it, it seems to be somewhere on the telephone line but not in my house. Like in the DSLAM or a switch somewhere or I don't know what else.

Could it be possible? Who can I ask to check ?

Originally Posted by essbebe

@engine9


Temp solution( may be permanent !)
Now see the PLUG going to the modem.
In the power adapter it will be marked
Inner +VE or outer +VE D.C
Observe the polarity.VERY IMPORTANT
Prepare another connecting cable of same type.
and connect Directly
One end to +ve and _ve terminal of battery 12V
and another to modem power point.

I don't understand how it would work. The modem would always be on battery and not on TNEB anymore right? How to I get the battery to charge?

It is possible that your local RSU/Exchange is not having adequate power back-up mechanism and so the connection is failing to connect during power failures.

Originally Posted by panchabhut

It is possible that your local RSU/Exchange is not having adequate power back-up mechanism and so the connection is failing to connect during power failures.

In this case I should not be the only one? I'll ask around if people have the same problem.

I don't understand how it would work. The modem would always be on battery and not on TNEB anymore right? How to I get the battery to charge?

Even if you don't connect the modem PSU adapter I don't understand how it would work. The modem would always be on battery and not on TNEB anymore right? How to I get the battery to charge?anywhere, how the UPS battery gets charged ,
when TNEB power is on
??? ( trickle charge or Float charge? any indicator lamp in the UPS? showing charging the battery ?)

The main idea : when power fails if there is a delay of more than 24 milli seconds ( or even less ) the modem connection is lost.
Check the transient time given for the UPS.

Originally Posted by engine9

In this case I should not be the only one? I'll ask around if people have the same problem.

Yes. If that is the problem, then similar issues would be faced by all in your locality.

Originally Posted by essbebe

Even if you don't connect the modem PSU adapter I don't understand how it would work. The modem would always be on battery and not on TNEB anymore right? How to I get the battery to charge?anywhere, how the UPS battery gets charged ,
when TNEB power is on
??? ( trickle charge or Float charge? any indicator lamp in the UPS? showing charging the battery ?)

The main idea : when power fails if there is a delay of more than 24 milli seconds ( or even less ) the modem connection is lost.
Check the transient time given for the UPS.

It shouldn't be the problem as it used to work fine few weeks ago with the same modem, same UPS.

Plus if it was a problem of timing the modem would pick up the connection right after the first reboot, but now, it just keeps trying.

I checked the stats on my line and they seems quite bad can someone confirm?:

down up

SNR Margin (dB): 6.0 6.3
Attenuation (dB): 56.5 45.4

Thanks

Originally Posted by panchabhut

Yes. If that is the problem, then similar issues would be faced by all in your locality.

In this case it doesn't seem to affect anybody else around.
Could it be a faulty line to the junction box ? or a faulty port in the DSLAM?

The more I think about it the less I can see where it can come from.

From Post No 1.

[/'ve a little problem with my dsl connection:

Everything works fine in general but when there's a power cut, my modem looses the dsl connection and doesn't manage to reconnect regardless that it is plugged on a UPS.

Now Post No 14.

checked the stats on my line and they seems quite bad can someone confirm?:

down up

SNR Margin (dB): 6.0 6.3
Attenuation (dB): 56.5 45.4

Your Line is bad. Call CC.

I know that it's weird the problem occurs only when the modem is powered by the UPS and that was my first guess for the source of the problem.

But I changed it, I even put the modem on a separate UPS and the problem is still here.

The only thing I didn't change is the cable that goes from my house to the junction box.

On the other hand I seem to be the only one with this problem so this is not an Exchange problem.

What test can I do to narrow the problem?

Originally Posted by engine9

meetdilip: As power cuts are really frequent in my area I have a UPS for the full house (fans, lights,...). It worked liked this for maybe a year. It just stopped 1 or 2 weeks ago.


I have the classic UTstar WIFI from bsnl (dataone), but I tried a NETGEAR (I don't remember the model) same result.

essbebe: I, like you, though it could be related to my UPS, but I managed to get an other UPS and it acted the same way.
Plus if main power is there but I switch it off in my house (the main electrical breaker) then the house is power via the UPS it works fine. The modem power supply is a 220V/12VDC, and I also tried a different one without any luck.

Instead of telling Classic UTstar modem, why not tell the model number?

I suspect that the filter capacitor (electrolytic) inside your modem might be dry. it can be observed by a small bulge on the top of the capacitors.
You may get them replaced by a local technician.

Originally Posted by mvs sarma

I suspect that the filter capacitor (electrolytic) inside your modem might be dry. it can be observed by a small bulge on the top of the capacitors.
You may get them replaced by a local technician.

he has already mentioned that he has tried using a different modem (including netgear ) to check if his modem is malfunctioning ...............

for some unknown reason it starts working better,
I still have some frequent disconnections when the power goes but it manages to reconnect.

Let's see how long it's going to last.

Ok,

So I still have the same SNR and attenuation but the sync rate are really better and the modem doesn't drop the connection while there's no TNEB.

Anyway thanks for your help.

Engine9

Please confirm, how the problem appears to have been solved.

Please check present SNR ATTN and Mod mode .
with TNEB power, and when standby mode is selected.
( any minor/major changes ?)

did u manage to get any clue as to how the issue was resolved?