First some background. Several months ago the phones in our house
went out. I figured out that it was a wiring problem inside the
house. I called the phone guy to fix it. He said that our phone
jacks are in series on two four-conductor cables. He said that there
was a short. At one of the phones (it must have been between two of
the phones), he switched to the other pair of conductors. He said
that if we had this problem again that we would lose the use of one of
the jacks, I think it was at the end of the line.
Recently our phones went out again, and rather than another expensive
call to the phone company, I decided to try to fix it myself, thinking
that it might be a similar problem. I disconnected the wires to one
of the jacks he had worked on, and most of the jacks started working
again. Only three jacks don't work - the one where I made the
disconnection and two more on that end of the house. One of those two
is apparently the end of the line, since only one cable is leading to
it (the other two jacks have two cables).
I need to get one or two of the jacks on that end of the house working
again, if I can. The problem is that I can't tell which cable is in
or out. And if there is a pair of live conductors on the in cable.
The only equipment is a volt/ohm meter. Is there a voltage across
working conductors? If so, what should the voltage be and is it AC or
Thanks, that enabled me to fix it. Most of the pairs didn't give any
reliable reading but then I found a pair with about 6 volts. I
wondered if that could be it. I kept checking until I found one with
53 volts, and used that, got it back. Thanks!
little gold-plated connectors in the jacks are corroded. My whole
house went dead a few years ago, and I found that the installer(s) put
the wall jacks in with the gold connectors on the down side of the
jacks. One of the jacks which was on an outside wall had accumulated
enough condensation on a hot, muggy summer day to short the connection
with a few drops of condensate and eventually, it corroded the contacts.
If they had installed the jacks with the contacts up and the release
tab down, it probably never would have happened. My point is, check
every jack internally to see if there is any corrosion or moisture
causing your problem
This is a common cause for trouble but usually takes YEARS to accumulated
enough crud to affect service. The offending outlet is usually on an exterior
wall, below grade. I have found such bad jacks behind aquariums, live plants
and under windows. (potential moisture source)
Awesome! After all these years, yours is the first GOOD reason I've ever
heard for installing phone jacks properly! I had never considered your reason.
On the other hand, I have replaced countless corroded jacks, properly
installed, that I suspect inverse orientation would have had little effect.
More good advice.
The OP's home is wired in a "loop" configuration. That is, a SINGLE run of
cable is LOOPED through each outlet (in-then-out). Of course, at the end is
what appears to be a SINGLE cable - the "dead" end.
Obviously (to many, I suspect), if the pair is opened at any point in the
cable, all outlets BEYOND the open will quit working. A short or other defect
ANYWHERE in the pair will affect ALL equipment on that line until the defect
If the OP cannot find the defect and has only ONE phone line, he can switch to
the spare pair (yellow/black?) immediately ahead of the defect and move all
affected outlets to that pair to reactivate them. Good luck!
I got the jack that matters working again, the kitchen wall phone. The
other two jacks are downline from that, but I didn't bother getting
them working since we haven't been using them anyway. If we decided
to try to use one of them, I know what to try.
I checked my phone line where it comes into the house, and found
positive on green. I think that's the "right" way to do it.
Most electronic phones have internal rectifiers, so they don't care.
Some early tone phones do care. Do you have one of those?
I'd do it right, if possible. Someone might want to use one of those
old phones someday.
1. I choose not to remind people of inappropriately replying by email.
This is not email.
2. The correct sig separator line is "-- ". Some newsreaders respond
properly to that.
With a white/green pair, it's right. With the older "standard" red/green
pair, the RED is the correct conductor for voltage.
Solid/good continuity to ground with no voltage should occupy the "tip"
conductor. (green of a red/green pair or white of a white/blue)
The "ring" conductor should have -48-52VDC-to-ground on it. You'll notice I
said NEGATIVE 48VDC. Everything in the C.O. battery room is labeled as
NEGATIVE. You tell me. <sigh>
Originally called a "polarity guard" when first introduced, you are correct.
Good advise, always.
I find email replies to my usenet postings a bit annoying. But, only a bit.
That is [hyphen] [hyphen] [space] [return] by itself at the beginning of a new
line. That line and everything that follows should NOT be copied/quoted when
using the quote function of a "compliant" newsreader.
Most good newsreaders should. Try quoting this message. (You don't have to
SEND it.) If my sig (smiley, "JR", etc) below is quoted, your newsreader is
NOT compliant with the standard. It's no big deal but quoting sigs is a waste
of bandwidth and is usually extraneous to the topic being discussed.
Tomorrow we will discuss lower-ASCII artwork. Class dismissed. <big grin>
Thank-you. It's probably basic electricity but I don't recall ever knowing
What in incredibly OLD technology. What other, equally old technology do we
use so massively, on a continuous basis? Electricity? The internal
Probably not. Only the very old Western Electric Touchtone<tm> sets required
proper polarity. If the polarity is reversed, these increasingly scarce
telephones can receive calls and be talked on but their keys will not sound
Color to color is the proper technique.
If the pair's polarity is reversed somewhere in the line before it enters the
premise, you can correct the polarity at the interface. All wiring beyond
should conform to the standard: green/red or white/blue should go to the
greed/red terminals on the jack. Black/yellow or white/orange should go to
the black/yellow terminals.
If connecting a block at a tap point (a loop in a loop-wired installation) be
sure to also splice the pairs "through". IOW, make a three-way connection to
the pair at the location to feed that jack, making sure to splice-through
extra/unused matching pairs.
OK, but I don't understand what you mean by a three-way connection.
The jack I got working was inside the loop. The blue/white pair of
conductors to the red/green of the jack got it working. For the time
being, I didn't try to get the next jack downline working, since we
don't use it. So how should the 3-way connection be?
Replace you know what by j to email
If you don't want the stuff "downstream" to work, or there is trouble on the
pair beyond that location, your connection at that location is known as a
"dead end", not a three-way. If you don't "connect through" the conductors of
the loop, you are "dedicating" the pair at that point. This is basic cable
splicing and applies to much common electrical wiring as well as telephony.
If you DO connect all like (matching) conductors, you are making a "tap" or
"three-way" (in-jack-out) connection. This is often done by placing BOTH
like-colored conductors behind the appropriate terminal screw of the device
(jack). Twisting them before placing behind the washer is poor technique.
Placing individual "hooks" of tinned conductor, each behind its own washer,
then slightly expanding/loosening/opening the hook before seating the screw,
is next-to-best. The best tap technique, from a reliability and ease of
trouble shooting standpoint is to connect a short length (8-12-inches) of wire
to the jack - a "stub". Then, using two jellied 3-conductor, solderless
connectors (Scotchlok<tm>), cut-in/splice-in the stub to the loop - a
A loop-wired home is probably the most confusing component to a DIYer doing
some of their first phone wiring work.
It is a VERY primitive scheme: If the house just disappeared, you would have
one, LONG length of cable. What appears to be two cables in an outlet box (or
plaster ring) is really just a LOOP of that ONE cable, the bulk of which is
permanently behind the walls and ceilings of the premise. Jacks are merely
TAPPED onto a SINGLE pair in that single cable at several points along the
cable. Lengths of cable can be tapped, or three-wayed, onto the main cable at
any point to serve one or more outlets.
After THIS class <big grin>, you'll want to attend my next one where we'll
cover the installation of a DPST switch that silences every station on the
teenline until the kids' homework and piano practicing are done. That can be
done from an SNID but having the switch mounted on the kitchen wall is the
I hired-on as one of Omaha's first, male long distance operators with the old
Northwestern Bell Telephone Company. Affirmative Action was 4-months old.
The job was right out of The History Channel: 20-30 of us, elbow-to-elbow, on
non-padded (wicker seat) chairs plugging cords into jacks on a half-block
long, black switchboard. I began wearing the "modern" (Mercury 7 era)
headset. It was eventually replaced by a Plantronics "Starset".
It was a trip. After several INCREDIBLY boring months of this, I amazed all
the women that had been plugging-away for 30 years, and had never seen such a
thing, by drawing an half-inch long ARC by leaning on the ringing key and
using another cord as the ground. Ahhhhh, the good, old days...
TeleTrivia: Although the first telephone operators were men, they were
eventually replaced by women because women were less likely to swear at the
customers or whittle on the switchboard.
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