Re: OT (most likely) strange modem disconnection when using USB drives

Tim:
Anybody think of other things to try?

Frank Cox:
That sounds to me very much like an electrical problem rather than an electronic
problem.

'twas one of my thoughts, too.

Your USB enclosure device is creating a ground loop or a short that
is causing your modem to disconnect. Your modem is apparently the only device
that you have that is sufficiently sensitive to be affected by this.

That thought had occurred to me, too. I tried the nasty trick to test
that: Plugged the USB enclosure into the mains through an adapter with
the earth pin ripped out. Made no difference.

Isolated PC (grounded), with monitor (grounded), keyboard, mouse, USB
enclosure, no other connections. Nothing to tie it to the any other
equipment, anywhere. I can't see how this would cause an earth loop to
the something in the other room.

I'm not sure where you are, but in Australia, the mains power is a live
mains feed from one of the three phases in the street, with the
so-called "neutral" being a current return path to the street (anything
BUT neutral), which is grounded from place to place along the
transmission lines, and the house's earth is grounded at the house
(typically to the water pipes), and joined with the neutral at the
fusebox.

The phone lines a twisted pair of copper to the exchange, all the way,
still, as far as I'm aware. I don't think they've updated the wiring
around here in 40 years. Grounded at their end, but not at this end.

Try switching the modem to a different electrical circuit and see if anything
changes.

Not possible, unfortunately. Everything's on the same phase. My only
choice, which isn't impossible, is to try running it from a battery.

My next step, were I you, would be to call an electrician and have him check
things out. Aside from the inconvenience, something like this could also be
hazardous to your house and your life.

Also on the agenda.

--
(This box runs FC5, my others run FC4 & FC6, in case that's
important to the thread.)

Don't send private replies to my address, the mailbox is ignored.
I read messages from the public lists.

--
fedora-list mailing list
fedora-list@xxxxxxxxxx
To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list

Relevant Pages

  • Re: Modem problem
    ... Appreciate why lightning may have found a path to earth via your ... The telephone line already has a superior protector ... a better earth ground. ... So how was a modem damaged - internal or external? ...
    (microsoft.public.windowsxp.hardware)
  • Re: blocking radio waves
    ... a mains live wire, then the current has a path through you to earth. ... not having a earth on equipment *inside* the screened ...
    (rec.radio.amateur.antenna)
  • Re: Electric shocks off PowerBook
    ... By which classification system is a laptop known as "class II"? ... A class I appliance has mains voltage, ... and must have full earth continuity from the case ... either mains voltage or low voltage, ...
    (uk.comp.sys.mac)
  • Re: Safety issue ? -Phonic Power Pod 1062,mixer amp, from 2002
    ... shock off the mains lead by touching the earth pin when just unplugged from ... There is no earth strap, ... The ground in such an amp is always relative, often the CT on the power transformer itself or back end of the bridge rectifier, quite possibly floating a few volts away from earth ground. ... It must be rare enough to satisfy regulators that the mains transformer fails open circuit but shorted to the case. ...
    (sci.electronics.repair)
  • Re: caravan charger u/s
    ... The latter can trip simply due to a small amount of leakage to earth. ... before doing so i noticed the wires were the wrong way round on the mains ... buzzing,no bangs,no lights -completly dead,checked the mains on/off switch & ...
    (uk.rec.caravanning)