Re: Weird modem problem

In article <MPG.20c804a626150c80989685@xxxxxxxxxxxxxxxxx>,
Charlie Wilkes <charlie_wilkes@xxxxxxxxxxxxxxxxxx> wrote:

The dial tone cut out when I plugged the rj11 cord into the laptop (SENS
LT56ADW Win Modem), and then came back when I unplugged it... This even
happened when the computer was totally powered down. Have I fried my
Win Modem? I don't think so because the Windows diagnostic can
communicate with it and does not detect a problem.

Charlie-

There is probably some kind of transient absorber in the modem,
connected across the phone line. There might have been a voltage surge
(lightning strike a mile away?) that was more than the absorber could
handle. It protected your equipment, but now is a short circuit across
the phone line.

There may also be a reed relay that connects the phone line to the
modem. These relays normally do not handle much current, so anything
like a voltage surge might cause the contacts to stick in the off-hook
position. However that would not kill the dial-tone.

In other words you have a short circuit. If you can get to the circuit
components on the modem card, it is possible you can isolate the cause
and repair it.

Fred
.

Relevant Pages

  • Re: Unattended Initiate (UI) and Round Robin (RR)
    ... > I need to learn about these two modem features/mechanisms but I can't ... RR is an extension of this, merely meaning the retrain would be ... accomplished in both directions on the 4-wire circuit. ... Constant Carrier means that the modems analog carrier signal is ...
    (comp.dcom.modems)
  • Re: Could a telephone line damage a modem ?
    ... > Electricity means a complete circuit. ... > through that modem. ... > damage is routinely avoided. ...
    (uk.telecom)
  • Re: pc circuit boards
    ... > I would like to undertsand something of the circuit boards in pc's. ... > Has anyone come across a suitable url which explains the ... they have a working computer without a case. ... They plug in the modem and run very specific software that injects known ...
    (sci.electronics.basics)
  • Re: Could a telephone line damage a modem ?
    ... > damage, first, one must establish some well proven principles. ... > Electricity means a complete circuit. ... > through that modem. ...
    (uk.telecom)
  • Re: Weird modem problem
    ... LT56ADW Win Modem), and then came back when I unplugged it... ... There may also be a reed relay that connects the phone line to the ... In other words you have a short circuit. ... LCD display became visible for a moment... ...
    (comp.dcom.modems)