Ethernet Cable Woes - On and Off every second

Discussion in 'Computer Support' started by davetonge@yahoo.co.uk, Feb 20, 2007.

  1. Guest

    Hi

    I am having some problems with a 40m CAT5 ethernet cable.
    When I first installed the cable, I tested it and it was working with
    no problems. I haven't used it in 10 months, and when I went to
    reconnect it I am having a problem. The connection goes on and off
    roughly once a second. So it will be on for one second, and then off
    for one second - continuosly!

    What can cause this problem?
    Could it be interference?

    Please help!!!

    Thanks

    Dave
     
    , Feb 20, 2007
    #1
    1. Advertising

  2. <> wrote in message
    news:...
    > Hi
    >
    > I am having some problems with a 40m CAT5 ethernet cable.
    > When I first installed the cable, I tested it and it was working with
    > no problems. I haven't used it in 10 months, and when I went to
    > reconnect it I am having a problem. The connection goes on and off
    > roughly once a second. So it will be on for one second, and then off
    > for one second - continuosly!
    >
    > What can cause this problem?
    > Could it be interference?
    >
    > Please help!!!
    >
    > Thanks
    >
    > Dave
    >
    >


    Dave

    Yes it could be interference.
    I had a case where a personal cooling fan took the whole LAN down when it
    was switched on.

    On the other hand a piece of cable left unattended especially if it is
    subject to movement of any kind could well have developed a break during the
    10 months.

    1 Try shutting down all but absolutely necessary electrical devices.
    2 Try substituting the cable.
    3 If problem still there substitute the LAN cards in the PC's


    Best
    Paul.
     
    news.motzarella.org, Feb 20, 2007
    #2
    1. Advertising

  3. writes:
    >I am having some problems with a 40m CAT5 ethernet cable.
    >When I first installed the cable, I tested it and it was working with
    >no problems. I haven't used it in 10 months, and when I went to
    >reconnect it I am having a problem. The connection goes on and off
    >roughly once a second. So it will be on for one second, and then off
    >for one second - continuosly!



    Is this solid or stranded cable?
    Did you punch it down to a patchpanel/jacks or crimp an end right on?

    I'd bet its solid cable with ends crimped on it, which does exactly
    what you see usually after some ammount of time of the crimps working
    just loose enough. (punching it down to a jack and running a
    patchcable is proper).

    Otherwise, there could be some interference somewhere, or you might
    have split the pairs and not wired it per spec?
     
    Doug McIntyre, Feb 20, 2007
    #3
  4. wrote:

    > Hi
    >
    > I am having some problems with a 40m CAT5 ethernet cable.
    > When I first installed the cable, I tested it and it was working with
    > no problems. I haven't used it in 10 months, and when I went to
    > reconnect it I am having a problem. The connection goes on and off
    > roughly once a second. So it will be on for one second, and then off
    > for one second - continuosly!
    >
    > What can cause this problem?
    > Could it be interference?
    >

    Most probably it is a autonegotiation issue. Try to set fixed speed/duplex
    modes on both ends, or try to change one NIC/driver combo.
    --
    vista policy violation: Microsoft optical mouse found penguin patterns
    on mousepad. Partition scan in progress to remove offending
    incompatible products. Reactivate MS software.
    Linux 2.6.17-mm1,Xorg7.1/nvidia [LinuxCounter#295241,ICQ#4918962]
     
    Walter Mautner, Feb 20, 2007
    #4
  5. Al Dykes Guest

    In article <45da8b32$0$58026$>,
    Doug McIntyre <> wrote:
    > writes:
    >>I am having some problems with a 40m CAT5 ethernet cable.
    >>When I first installed the cable, I tested it and it was working with
    >>no problems. I haven't used it in 10 months, and when I went to
    >>reconnect it I am having a problem. The connection goes on and off
    >>roughly once a second. So it will be on for one second, and then off
    >>for one second - continuosly!

    >
    >
    >Is this solid or stranded cable?
    >Did you punch it down to a patchpanel/jacks or crimp an end right on?
    >
    >I'd bet its solid cable with ends crimped on it, which does exactly
    >what you see usually after some ammount of time of the crimps working
    >just loose enough. (punching it down to a jack and running a
    >patchcable is proper).
    >
    >Otherwise, there could be some interference somewhere, or you might
    >have split the pairs and not wired it per spec?


    For properly wired cable, IMO, You'd have to be working right next to
    welding or high-power radio equipment to even *think* about
    interference.

    How do you know the "once a second" bit?

    --
    a d y k e s @ p a n i x . c o m
    Don't blame me. I voted for Gore. A Proud signature since 2001
     
    Al Dykes, Feb 20, 2007
    #5
  6. In comp.dcom.cabling news.motzarella.org <> wrote in part:
    > Yes it could be interference. I had a case where a personal
    > cooling fan took the whole LAN down when it was switched on.


    Totally believeable if a cable near the fan had a split pair.
    Otherwise not.

    -- Robert
     
    Robert Redelmeier, Feb 20, 2007
    #6
  7. Wrolf Guest

    On Feb 19, 8:20 pm, wrote:
    > Hi
    >
    > I am having some problems with a 40m CAT5 ethernet cable.
    > When I first installed the cable, I tested it and it was working with
    > no problems. I haven't used it in 10 months, and when I went to
    > reconnect it I am having a problem. The connection goes on and off
    > roughly once a second. So it will be on for one second, and then off
    > for one second - continuosly!
    >
    > What can cause this problem?
    > Could it be interference?
    >
    > Please help!!!
    >
    > Thanks
    >
    > Dave
    >



    Very difficult for it to be interference. Is it Cat 5, stranded,
    correct wiring (EIA/TIA 568B or 568A)?

    Try isolating the problem with a laptop, Fluke, or other Ethernet
    device. When you go through the cable, do you get the fault, or is it
    only with the user equipment? If only with user equipment, then that
    is the problem. Then move the test equipment to the other end of the
    cable, plug in to the switch or whatever is at the other end using the
    same patch cables. If you still have a problem, the cable is
    innocent. Only if the problem only occurs when the cable is in the
    path, blame the cable.

    If the cable is indeed to blame, the chop off BOTH ends, reterminate,
    and test with a tester. You should probably also test your tester
    against some known working good cable. Make sure you use the strain
    relief.

    If it still does not work, chop of BOTH ends, and run new cables. You
    might want to use the old cable as a wire drag, and get it out. Most
    of the time you just leave the old one in there, but you definitely
    want to chop off the ends to prevent accidentally using it.

    Wrolf
     
    Wrolf, Feb 22, 2007
    #7
  8. Dmitri Guest

    Al Dykes wrote:


    > For properly wired cable, IMO, You'd have to be working right next to
    > welding or high-power radio equipment to even *think* about
    > interference.


    > How do you know the "once a second" bit?


    I agree with Al. These cables and associated equipment are usually pretty
    resilient to interference. I think you should look into simpler issues
    with the network configuration. There may be couple devices with the same
    IP address on the same subnet or the equipment is trying to re-negotiate
    speed or duplex mode or a similar networking related issue and not the
    cable. Especially considering the regularity of the problem. Interference
    issues tend to be random except of course when the source of EMI is
    switched on and off regularly itself.

    --

    Best Regards,
    Dmitri Abaimov, RCDD
    http://www.cabling-design.com/
    Home Cabling Guide, Cabling Forum, color codes, pinouts and other useful
    resources for premises cabling users and pros



    --
    +--------------------------------------------------------------------
    | http://forums.cabling-design.com/
    | *** a better way to USENET ***
    | no-spam Web and RSS interface to your favorite newsgroup
    | 24hoursupport.helpdesk,comp.dcom.cabling - messages and counting!
    +--------------------------------------------------------------------
     
    Dmitri, Feb 27, 2007
    #8
  9. Al Dykes Guest

    In article <b%ZEh.27931$>,
    Dmitri(Cabling-Design.com) <> wrote:
    >Al Dykes wrote:
    >
    >
    >> For properly wired cable, IMO, You'd have to be working right next to
    >> welding or high-power radio equipment to even *think* about
    >> interference.

    >
    >> How do you know the "once a second" bit?

    >
    >I agree with Al. These cables and associated equipment are usually pretty
    >resilient to interference. I think you should look into simpler issues
    >with the network configuration. There may be couple devices with the same
    >IP address on the same subnet or the equipment is trying to re-negotiate
    >speed or duplex mode or a similar networking related issue and not the
    >cable. Especially considering the regularity of the problem. Interference
    >issues tend to be random except of course when the source of EMI is
    >switched on and off regularly itself.




    I still want to know ow the OP determined the "once a second" bit.

    --
    a d y k e s @ p a n i x . c o m
    Don't blame me. I voted for Gore. A Proud signature since 2001
     
    Al Dykes, Feb 27, 2007
    #9
  10. Al Dykes wrote:

    .....
    > I still want to know ow the OP determined the "once a second" bit.
    >

    The blinkenlights on the switch or the network card?
    However, the OP appears to have lost the thread.

    --
    vista policy violation: Microsoft optical mouse found penguin patterns
    on mousepad. Partition scan in progress to remove offending
    incompatible products. Reactivate MS software.
    Linux 2.6.17-mm1,Xorg7.1/nvidia [LinuxCounter#295241,ICQ#4918962]
     
    Walter Mautner, Feb 27, 2007
    #10
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Peter
    Replies:
    2
    Views:
    1,102
  2. Dima

    PC pauses every 1 second. Plz help

    Dima, Sep 16, 2004, in forum: Computer Support
    Replies:
    2
    Views:
    1,921
  3. Replies:
    0
    Views:
    594
  4. Replies:
    6
    Views:
    1,230
  5. John Corliss

    Hard drive light keeps flickering about every second.

    John Corliss, Jan 29, 2008, in forum: Computer Support
    Replies:
    22
    Views:
    4,144
    ClueLess
    Jan 31, 2008
Loading...

Share This Page