Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations strongm on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Phone line dead by modem

Status
Not open for further replies.

Guest_imported

New member
Jan 1, 1970
0
Hello! I have a weird question. Can a modem kill my phone line? I have call waiting on my phone line and I connected to the internet as I do every day, but, yesterday after disconecting from internet the line went dead. I then use the wall jack extension from another room and after disconecting, the line is dead also. So I lost two line extensions from two rooms when I connected to the internet. Is it possible for a modem to just kill those line wall jacks? Please help me with this problem.

Thank you!
 
When you say dead, do you mean that you've also tried plugging in a phone and it doesn't work?
I wouldn't have thought that a modem could kill a phone line, but then I'm no expert on modems.
Are these phone lines at home or at work?
Is there a chance that you have voice mail waiting on these lines?

Any other info like this would be helpful...
 
Thanks for answering!
This is my home phone line. And there is no tone when I plug the phone in. The line went completely dead. It happened to tow diferent line extensions at home. Just after using that line for internet they went dead. I scanned my pc for virus and is cleaned. My virus definitions are up-to-date. The weird thing is that this only happened to a phone line with call waiting service. I have another line at home with no call waiting service and it works fine. Any info will be very appreciated.

Thanks again for answwering.
 
Is it possible that the phones you are using are dead?
Can you still connect to the internet?
I can't imagine that a modem could damage your phone line. Seems a bit drastic (maybe sue the modem company LOL ).
I don't think that virus's could do any damage either.

Have you contacted your phone company? Maybe they don't allow people to use the internet on certain lines, and if you do they might cut you off?

Let me know how you get on.
 
I've never heard of a modem being able to "zap" a phone line and I don't think it's possible. If you are plugging a definately functional phone into the jack, and it doesn't work, then it's either the jack or the phone cord. Try using a known-good phone cord and plug the known-good phone into the jack. If it still doesn't work, then I'd say your jack, or the wiring that connects it from the street is bad.
I agree with "thatrenowned" about contacting your phone company in this case, although I strongly disagree about the notion that the phone company "wouldn't allow" certain lines to be used for the internet. The phone company just provides the lines, they don't know if your using it to talk or to dial up, or what.
Since you said you just had service added to the lines that are no longer working, I'd say the telco is the place to start.
 
I have t o agree with Crisc and thatrenowned, a call to your local phone company is in order. A modem I doubt could generate enough voltaage to take out the local telco switch at the CO. More likely is that as with call waiting you hang-up to receive the other call. It seems though the telco thinks you have not hung-up. FOr some advise I would remove call waiting on any phone you use for dial-up. Good luck.
 
I have seen this happen to me at home. I went outside and pulled the access panel open for the phone lines, removed the plug-in that goes to the house and plugged it back in. Then it was fixed. I think this is caused by moisture in the air and corrosion or dust settling on the plug-in. It could be a grounding issue also. I thought my computer or phone had gone batty or someting, but it was easily solveable. If you do not like my post feel free to point out your opinion or my errors.
 
I've seen phone lines go dead when the modem had an internal short. Machine powered up, phone line went dead. Most cases the line went onhook when the modem was disconnected (unplugged from the line), but on 2 or 3 it took hours, and on one occasion it took the phone company to disconnect the line then reconnect.
Do you have the service entrance demarcation disconnect? If so, how about trying a phone from there? That takes all other potential house wiring problems out of the picture. Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.
 
I have seen modems hold phone lines down so long as they were connected to the phone line. Every now and again in my job in tech support, I'll get one of these calls where the phone line works if the modem is disconnected. I didn't see it mentioned if the modem was disconnected and then the line tested. Might be worth trying. I've never seen a modem kill the line, though and I've seen modems do alot of strange things. (my favorite is when the phone conversations play through the computer speakers if the phone line is attached to the modem).
If the line is dead after removing it from the modem, call your telco. They'll blame you, your phone, your computer, your aunt in kalamazoo, but eventually they'll send someone to look at it.
good luck. hg
 
Yeah, I also disagree with that statement I made about the phone company cuttin you off for using the internet on certain lines. Surely, if this was the case, they would have informed you....(I was just running out of ideas X-)).
Still very much worth seeing if the phone company has cut off certain lines and definately check that the phones you're using aren't knacked. I know I'm repeating what I and others have already said, but it seems to be the most likely reason for the problem.

Regards...
 
You say that two extensions went dead, do you have any other ext. for this number that still work?

If not, I'd call TelCo immed. but I wouldn't mention anything about a computer or modem killing your line. Just tell them you don't have dial tone.
 
I've had the same problem with a customer of mine. We found that the problem persisted so long as the modem was physically connected to the phone line and mysteriously disappeared when we pulled the plug. The client has 4 seperate lines that and 2 went dead when this happened.

We went through the phone company for initial resolution and the tech claimed it was the modem right off the bat, he claimed that the two lines that would go dead shared space in the network junction box in his house and we should call 3 COM. I will say that the 3 Com tech didn't seem too surprised by the announcement and was happy to replace the modem, problem solved.

Hope this helps
 
I had the same problem with a normal phone that I externally power. When the pohone is connected, line dead. Still, the line recovered afterwards.
Opening the phone, it appears that the phone has no line transformer. This is technical - connecting the external power supply, which had its ground earthed - appears to earth the phone, and with the phone the phone line.
Result: line dead.

All faulty modems etc. seem to me you are somehow having a bad isolation between the modem & the phone line. Did you try to run the PC on batteries only? (even though this is not a permanent solution; you better change the modem )

 
You could try checking for voltage on the line. On hook it's usually around 50v dc, off hook approximately 10v dc and a ringing line could give you upto 100v ac. It sounds like your modem could be faulty and has tripped out equipment at the exchange (hub).

Get your telco to run a check on the line...


ROGER - GØAOZ.
 
I have seen this happen before on several computers. Usually if I disconnect and try to use the phone and have no dialtone I can look back at my computer and see that the icon for my connection has not disappeared. All this takes is a reboot of the computer.

As for the call waiting that is a problem waitin to happen. Your telco should have a number to dial to disable/enable it. On my one line that has call waiting when I use a computer on the net I make sure that I disable the callwaiting first. (incoming calls can cause the connection to drop and that gets VERY annoying when you are at 95% of a large download)
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top