Think of this page as
learning Service Call Stress Reduction!
What's the first thing NOT
Don't replace the KSU!
Read the FREE information we have
here, think about the problem, and do some testing...
With this information, your stress level will go way
down because you'll know how to find what's causing your customer's problem.
We don't have "magic"
gizmos. If you look at our web pages, read
our Technical Bulletins, have some spares, and you already have a fairly good
digital meter, you can probably fix a lot of the problems you encounter - for FREE!
If you want to be a successful Repairman, you only need to
remember and practice ONE THING...
START AT THE BEGINNING
We're not talking about saving a few minutes by doing basic
troubleshooting instead of guessing. We're talking about many hours of wasted time,
when you could have found the problem quickly by just starting at the beginning (I
speak from experience!).
In order to start at the beginning, you need to have a
clear picture in your mind of how the gizmo you're fixing is connected, so you know where
the beginning is and the next thing to check.
To fix a phone line, it might be the telephone company or
channel bank to the NI (Network Interface), to the lightning protector and ground, to a
mod jack, to the CO line card, to the CO line (or system wide) programming on the system
for things like attenuation, impedance, echo cancellation, and CPC, etc.
You also need to
think about any external stuff connected to the phone system, like the AC power, battery
backup, ground, other phone lines, stations, paging etc. All of the external gizmos
connected to a phone system can be causing a problem on the phone system - so you want to
get them disconnected to make absolutely sure they're not causing your problem.
If you leave out something, Murphy's Law says that
will be the problem (that you'll find many hours later). Making yourself a list or drawing
a picture of how everything is connected might be a good idea when you walk into the job.
Simply stripping a system down and adding
everything back one thing at a time until the problem returns, is the best way to
troubleshoot a problem.
I know you don't want to do this. You'd
like to poke around at the easiest stuff first. You can do that, but if
you find the problem it will usually take longer than if you started at
the beginning and did your troubleshooting in a methodical manner.
Fixing a system today by stripping it
down and starting at the beginning is much easier than in the old days
of 1A2 (with 25 to 100 pair cable). On a 1A2 system, you could have 30
or more phones that were all the lines were bridged together. If a line
wasn't working right, you could disconnect the line card in the 1A2
system from all of the phones by pulling one set of jumpers. If the
problem went away, one (or more?) of those 30 phones had a problem
(often a water damaged 25 pair connector that got wet when mopped).
You could guess at which phone it was and
start taking apart connectors to see if they were green inside (you
couldn't see the water damage from the outside), and if you got it on
the first five tries you would have gone out and played the lottery. It
was your lucky day.
The only reasonable way to find the
problem was to start removing the 3 pair jumpers to a line on a phone,
one at a time (marking them so you could put them back in the same
position on the 66B block). Remove a jumper, test to see if the problem
cleared, and if it didn't go on to the next jumper. If it cleared, you
trace that jumper to the cable, then look at the floor plan to see where
the cable was. If you were having a really unlucky day, the bad phone
was the 30th jumper.
Modern systems are much easier!
So you've got a strange problem. Since you've probably got dozens or hundreds of the
particular model of system you're working on installed, and the problem isn't occurring at
those other places, there must be something different about the place you're at. All
you have to do is find what's different!
Phone system hardware (from traditional phone system
manufacturers) is more dependable than ever. The cards and power supplies just don't break
like they did in the 80's and 90's. While the problem you're looking at might be caused by
a bad card or power supply, it may just be an interaction with something that's connected
to that particular phone system, at that particular site.
Since the phone system by nature has to connect to the
outside world, the interface to the outside world is likely to be causing some problems.
It's easy to check the power on a system by simply running the system on the battery
backup to see if the problem clears (it's not a bad idea to carry a cheap battery backup
in your truck for testing). Removing the system ground is also a
good thing to do. The AC ground is already disconnected as soon as you pull the plug from
the wall on the battery backup/UPS, to run the system on batteries. Unless you put it in
yourself, it's hard to know whether a ground is good! Just because it's a green wire, it
doesn't mean it's actually connected to a good ground, or even anything at the
Fixing an odd problem could be as simple as reversing the
tip and ring on a CO line (especially from a channel bank or VoIP box), an external page
port, external bells, or an MOH/BGM port. Ground loops can cause strange
problems. Leaving one external device connected to a system that you thought you had
stripped down could cost you hours.
Although it might seem logical to assume
something in your troubleshooting process (like "I've never seen one of those go
bad" or even "The AC outlet must be wired right"), assuming anything
without checking it in its turn in the troubleshooting process
has led a lot of guys to chase their tails for hours or days.
We can all remember chasing our
tails! Just about every time I've assumed something, I got sidetracked and
the problem took longer to fix. Sure, I still do it sometimes (it's human nature), but not
While it might sound harder to always Start
at the Beginning, you get used to troubleshooting that way and wonder why
you wasted all that time in the past!
One other thing... Always
try your new tester at your office or home before trying to use it at the customer's site!
Once you know what your meter readings are
supposed to look like, you'll feel confident using testers to solve your customer's
If you remember, believe, and practice what you've just
you'll be able to fix anything!
I've walked into a lot of jobs where
the system was down, and the customer was going nuts. If I took the queue
and started acting
nervous and stressed, things would have gotten worse. When I go on a service call the only
thing I know for sure is that the problem can be fixed. There's no question about it. That
pretty much gets rid of the stress for me, even if the customer is acting nuts.
On the drive over to the service call,
I get a picture of the system in my mind, and think about where to start and how to
proceed. I do get screwed up occasionally when the person who took the service call wrote
down the wrong problem, or didn't ask enough questions. Sometimes I'll call the customer
when I'm on the way just to verify the problem (and let them know I'll be there shortly).
Sometimes I'll go pick up some parts before I go on the call. The amount of traffic in
bigger cities makes it pretty tough to go back to the shop for parts, as it would in a
more rural area where it might be a 100 or more mile drive.
I personally would never agree to
service a system that I didn't have spares for. If you need the spares from
the trade-in on a system
you're proposing, that's a good reason to give someone a good price on
the trade-in. It's
still going to be pennies on the dollar. Considering how many used systems are out there
from brokers (or ebay), having a whole working system (with at least one
station and trunk card) as a spare isn't expensive. It turns a stressful job
(telephone repair) into a fun job. You don't need to have every software revision, just
something to do troubleshooting and substitution with, and something to get the customer
up and running until you get the right software version.
Most Interconnects can't have full
systems as truck stock for every type of system in your base. If you have a few trucks,
it's not a bad idea to keep one type on each truck, so they can bring it over where
needed. Making a deal with a cab company or delivery service to deliver a KSU, common
cards, and power supply to a job site in an emergency is also a good idea (as it is when
you forget something on a cutover).
Every Interconnect has to deal with the
problem of bad cards getting mixed up with good ones. In the heat of battle, while you're
swapping cards, it's not hard to lose track of them since they all look the same. I carry
both gray electrical tape, and tags with string (don't use tags with wire!). The gray tape
is easy to stick on a card or the bottom of a phone, so I can write down what I did and
the date and time I did it when I swap something. If there isn't already a tag on a card I
take out of truck stock, I put some tape or a tag on it so I know it was from the truck.
If you do lose track of which card is
which, having the whole system lets you test the cards in your shop before returning them
to stock. There's nothing that screws up a repairman more than having bad cards for
spares. It's something to avoid at all costs.
I get a lot of calls
from guys asking me all of the possible things that could
cause a problem before they even go on a service call.
Then they want me to give them the solutions to each possible problem.
That would be really hard! You're causing yourself an incredible
headache to do that before a service call. You've got to start at the
beginning, find the cause of the symptom, and then start
trying to figure out what's causing it.
Every service call I go on is a
challenge, but it's fun because I know it'll be fixed soon, and I get to go on to the next
job. It's kind of like being a detective and surgeon in one job - but a lot
safer! What scares me is seeing a doctor
that doesn't know how to troubleshoot... And there are a lot of them out there.
Disconnect the phone line from the
equipment and test the line with your Butt-set. That's basic troubleshooting, but there's
more reasons to do it than just to see if it's the Phone Company's problem.
A Butt-set (or old 2500 set) is line
powered, so it has no reference to ground or AC. That's important, since some of the
problems you encounter will be an interaction between the phone line and the telephone
equipment, caused by the telephone equipment's reference to ground and "foreign"
voltages (like 110VAC). Every phone system will be slightly imbalanced. That means either
the tip or the ring is longer than the other side of the pair, or it can have a small
foreign voltage on it from being connected to the phone system. In most cases, this
doesn't cause a problem. In some, it does - and those are the cases you'll be on.
Calling the Phone Company and asking them
to "Check the Line" or take readings for you is generally a waste of time.
They're trained to say "It tests OK" no matter what. If there's
a problem with a Phone Company (CLEC or ILEC) line, it's generally your responsibility to
tell the Phone Company exactly why the line is bad. If you give them the numbers, they
generally won't bullshit you. Hey, if everybody could do this, they wouldn't
A common trick from Phone Company repairmen
is to tell you that your phone system is imbalanced or putting out a foreign voltage or
ground. No shit. The testers they use are made for testing lines
that aren't terminated. When they hook up their meter (that's
made for testing unterminated lines), they're reading the phone system as well as the
copper wire. They're supposed to open the line going into the premise before doing most
tests so they don't read the CPE (phone system) - which will always read something
strange compared to a regular 2500 set (that has no reference to ground or foreign
I've seen Phone Company guys tell the
customer they're disconnecting the line going into the building because it's damaging the
telephone network. What a bunch of bull. Some of their test equipment will "stress
test" the line, which puts out a pretty high voltage/current to try to cure problems
with a copper cable. Although that usually won't hurt a phone or system, they're
supposed to disconnect the CPE before they do the test. As you can guess, most Phone
Company repairmen don't disconnect the CPE. They don't care. They don't have to. Thanks
Fixing phone line problems is usually as
simple as finding what's different about that line(s) that's having the problem, compared
to others working in that system at that or at another premise. It's as simple as taking
some readings (testing), and comparing the results to other lines at that premise, or at
your other customers' sites.
Don't replace the
So this is what
I would do first on a strange case of trouble. I've seen a
lot of strange stuff, but there's no way I'm smart enough to fix a
strange problem without taking some measurements to lead me in the right
direction. Once I find the solution, I might try that on the next case
of trouble that's exactly the same - but you can really
chase your tail for hours if you don't take a couple of minutes to take
some basic readings.
This is the easy part:
Click to view and print
Telephone Line Diagnostic Table PDF
It's as easy as taking the readings for on and off-hook DC
voltage, loop current, AC, CPC, and Circuit Loss, and writing the results down on a piece
of paper. This lets you compare the results to other lines at the same premise, and at
other (working) sites. The problem will probably just jump out at you, and you'll know
what to look at to fix the problem.
Filling out this chart is very important these days because
customers are switching from the LEC (or ILEC - Incumbent Local Exchange Carrier, or the real
Phone Company) to a CLEC (Competitive Local Exchange Carrier, like Mike's Phone
Company). In most cases, the customer doesn't call you up to ask if it will work OK. They make
the change to save a few bucks, and call you when things don't work right (and then spend
the next two years' savings on your T&M).
By having a chart of the readings
you'll have a basis of comparison when the
customer switches the lines to a CLEC
and they don't work right.
You should also check the programming or jumper options for
the trunks or trunk cards. You'd want to check the Open Loop Disconnect (CPC) time, any
impedance settings (like 600 or 900 ohms), attenuation settings, echo canceller settings,
and anything else that can effect the operation of a trunk.
If you want to know the location of a Central Office, the
type of CO, who owns the CO, or even how far the premise is from the local CO, click
to see our Central Office (CO) Info Lookup
page to get the address of the CO, and use the Map
It! button figure out the distance between the two addresses.
In my opinion, you should automatically fill out the Telephone
Line Diagnostic Table for every new installation, whether you're having problems
or not. I actually recommend taking the time to do it before you propose a
system, so you know if you're in for trouble before
you quote the new system! It won't take long before it will take you just a few
minutes to fill out the chart, and potential (expensive) problems will just jump out at
My suggestion is to use our Installation Checklist before
every job you propose. Customer's can have expectations about
their phone system that they forget to tell you, or your system may just not do something
the customer assumes it can do. Using the Installation Checklist can
really prevent arguments, especially the ones where the customer says he won't pay you! Click to go to our
Installation Checklist - BOOK and DISK.
We have a bunch of phone line testers that are small, cheap
and line powered. We're pretty sure most of you aren't going to go out and buy a $500
tester, but by buying one of our inexpensive testers every once in a while to add to your
kit, you buy a $500 tester one function at a time - as you need it. To see the various
tools and testers we have for checking phone lines... Click to go to our Testing and Repairing Telephone Lines Page.
Most strange phone line
problems can be diagnosed by taking these simple readings!
Sometimes we just get lost in the heat of the battle, and
just need to talk about it. This ain't like the old days where you had a boss or tech
support guy working for your company you could talk the problem over with.
If you've stripped the system down to the basics and taken
all the voltage and current readings and you still can't figure it out call and ask for Mike
Sandman at 630-980-7710. I'm going to ask you for the numbers (results) from
the tests to see if I have an idea of how to fix your problem. Getting the numbers and
stripping the system down (to start at the beginning) is what I would do if I was there.
I'm not a genius, and there's no magic. There's no way I could fix your problem without
doing the basics if I was on the service call myself.
If I go on a service call I
know I can fix the problem. Since I know every problem can be fixed, I
handle even the worst service calls quickly and without a lot of stress. If you're not
excited and stressed (or don't show it), even with the customer breathing down your neck,
the customer will have less stress and probably let you do your work. If you explain to
the customer what you're doing (show him your chart?), and why you're going about it in
the manner you are, that might go a ways to calm an excited customer down. And then again,
some customers are just going to figure that every phone man knows magic, and should be
able to fix anything in a minute.
If you call me, I'm still going to know that
your problem can be fixed. I'm just going to ask you to do the things I
would do if I was there. If you haven't taken the measurements, read the
tech bulletins, and started your troubleshooting at the beginning,
you're wasting time for both of us - and your customer too.
Every service call you get under your belt is one
step closer to having a stress free job!