atcomsystems.ca/forum Forums General General Telephone & Systems Information Fax interference

Today I got a trouble call from a customer who has a small office with Samsung phones and a few computers. I wired the office, installed the phone system and computer network, and documented everything, so I know wuzzup.

There are plenty of jacks, typically 4-ways at each location, with one system jack, one RJ-11 for ancillary equipment such as personal answering machines, fax machine, credit card thingie, etc, and two ethernet jacks.

He states that on incoming calls to the main number, the answering machine answers, and he hears a fax machine answer, also. I ask "Have you done any moving of wires, plugged anything in or out recently...added anything?"

He says "No".

He left the door unlocked this evening, so I could have access after hours. I go there and find (1) the original fax machine still plugged into its proper single-line jack. (2) a second fax machine, plugged into a splitter, along with a Prostar phone, and thence into a system jack, and (3) a third fax machine, plugged into a single-line jack energized with the main number (from a previous answering machine hook-up).

I unplugged the two extra fax machines, and locked up the office.

Tomorrow I will ask him what he meant by "No".

Art, it's short for "don't kNOw nothin'"

That just illustrates why you can never depend on the customer's description of a problem.

-Hal

I think this story rather illustrates why people like you are so valuable. Troubleshooting is an art that cannot be taught. Like a really good mechanic or someone who draws well, sharing techniques and experiences goes only so far. The intuiive ability to "baseline" a problem by studying a backboard or by a minute's worth of experimentation can only be duplicated by those born with similar God-given abilities.

I don't think the customer was attempting to deceive you. My thoughts are that the customer simply didn't make the connection between cause and effect. This kind of thinking comes easily for you and I, which is why you are confused by his answer. Don't be. You're smart in this area and that is the end of the story. Stay humble, but make sure that you are compensated for this skill.

Tim, well said.

Our educators are taught to teach, not think. I had a school district asst. superintendent with fax trouble tell me Embarq found no problem. I checked, the alarm was on the fax line. Was the alarm on? She asks the High School Honcho. He says "NO". Yep, your correct, it was on, in alarm, and the fax didn't work. Gee, you think?

How to fix? Two options...fix the alarm or get another line for the alarm and leave the fax alone. They wanted a new fax number? Why? Everything has the old number on it. Logic and thinking are not always for the highly educated.

The trouble-shooting went like this:

Check original fax machine to see if it had the proper number on it. (Yes.)

Check main number on system phone and answering machine. (Verified correct number)

Do a quick "ear" test for metallic cross between fax line and main line. Dial 1004 Hz on fax line, pick up main line, dial silent battery, listen for cross. (No cross-talk or other noises.)

Test fax machine. (Works fine, both send and receive.) No other symptoms. But now we need to find where the fax machine is that is causing the problem.

Open main number at NID, and dial into main number. (No answering machine, and no fax machine answering.) This proves that the unknown fax machine that is answering is not doing so at some point along the pair before the NID. I had wondered if someone at another building had installed a fax machine or an alarm panel on a bridged cable pair with a left-in drop. It would have been a long-shot coincidence, but weirder things have been known to happen. It also proves that the offending machine is somewhere on the premises.

Put NID back to normal, and make a second test call, just to eliminate evil spirits, mental illness, repairman confusion, etc. (Same results: answering and fax machines both answer.)

Do a physical inspection of premises. (Found second fax machine plugged, via a splitter, into an EKTS jack.) This is confusing, because at the same time that I think "Aha!" I also tell myself that a fax machine plugged in this way could never ring up. On a Panasonic and some other systems, the W/Bl pair has dial tone, but not on a Samsung system jack. False alarm...but why is this second fax machine here? Must ask customer in AM.

Then I find a THIRD fax machine. ARGHHH!!! Is this all a bad dream, or an episode of Candid Camera? Why a THIRD fax machine? I check its cord for dial tone, and identify it. (It's line #1, the one in trouble.) A second "aha!" and this time, I can clear the trouble. Now, I need to ask customer why he has TWO extra fax machines.

I suspect that three people all want to be able to fax from their desks. The machines are combination scanner/copier/fax/printer. But this office is not huge -- about 800 square feet -- so getting up and walking over to THE fax machine is not a big deal.

My helper, a young genious with limited telephone experience, but endowed with a great analytical mind, suggests that they just plugged in cords due to the Sir Edmund Hillary syndrome: "because they were there." They might not even have needed fax capability at those two desks, but they saw the jacks, and assumed that to make a photocopier or printer work, they needed a dial tone.

The interesting thing about the symptom: Both the fax and the answering machine were set, by default, to answer on the fourth ring. If either had not been, an even weirder situation would have presented itself.

Dagwood, I appreciate and am humbled by your kind words about my trouble-clearing skills, but what makes this so frustrating is that I did not really clear a "trouble" but rather just undid some plug-confusion. These folks are my neighbors (literally) and good friends of my family. It is a small town. I often wonder if I should charge anything for doing these things, because the customer just inflicted this on themselves, and to charge them for something so trivial as unplugging a fax machine seems a bit mercenary.

Arthur,
"It is a small town."
There's your problem, "Inbreeding". No, just kidding, but I HAD to say it.
Actually, I'd almost bet money that your assistant is correct. At least partially. Your contact quite possibly had no idea that this other stuff was plugged in. And God help you if any of those 4-in-1's don't work Monday. It'll be your fault, even though they haven't worked since the day they came out of the box! John C.

Arthur -

Textbook troubleshooting. Perfect.

Sam

I normally don't put any extra jacks on a fax line, just the one by the fax, sometimes a CC terminal. Matter of fact unless a jack has it's intended device present while I'm there it doesn't get connected to anything. When something gets moved the old jack gets disconnected.

-Hal

Hal. I agree. This office has two separate wiring "systems". The original quad wire with RJ11's and the new 4-pairs that I ran. I needed to keep the old stuff energized during the transition to the new system, and at several desks, there were single-line answering machines. The office has three different business entities working out of it, so three answering machines was a normal situation.

I got tricked because they unplugged one machine, moving it to another corner of the office, leaving a live jack, and that's the one they plugged one of their legion of new fax machines into.

I had an "open and frank exchange of views" with them on Saturday, and admonished them to call me when they next feel the urge to play telephone man. The boss treated me to lunch. Case closed.