Telos ZephyrExpress user manual General, Thinking About Problem Solving

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ISDN TIP!

You can check ISDN continuity with an ordinary telephone or pair of 600 ohm headphones. Disconnect ZephyrExpress, and briefly place the phone (or phones) across the line. You should hear a rhythmic clicking Ñ about once per second Ñ or a loud, continuous white noise. If you hear a dial tone, itÕs not an ISDN line. If you donÕt hear anything, the line is dead.

ISDN TIP!

Are you sure youÕre plugged into the right port?

For most US installations, the line should be plugged into the lower, 4- conductor jack on the back of ZephyrExpress Ñ even if the phone company supplied an 8-conductor RJ-45 jack with the line. Use a standard telephone line cord: when you plug it into the RJ-45, itÕll automatically center itself and locate to the right conductors.

GENERAL

Thinking About Problem Solving

Despite best intentions, something could always go wrong. Sometimes troubleshootinga balky set-up can make even the toughest engineer a Maalox and Rogaine addict.

You can’t fix any system without the right world view; a zeitgeist of suspicion tempered by trust in the laws of physics, curiosity dulled only by the determination to stay focused on a single problem, and a zealot’s regard for the scientific method. Perhaps these are successful characteristics of all who pursue the truth.

In a world where we are surrounded by complexity, where we deal daily with equipment and systems only half-understood, it seems wise to follow understanding by an iterative loop of focus, hypothesis, and experiment.

The notions here apply whether you are solving problems at the system level or at the component level. At the system level, the actions you might take would be very different

– checking cables, trying different menu settings – but the thinking is the same.

Too many times, we fall in love with our suppositions. We are quick to overtly or subcon- sciously assume the problem being chased is due to lousy design, the stupid phone company, or the manager’s latest memo.

Armed with a healthy skeptical attitude, the basic philosophy of troubleshooting any system is to follow these steps:

1.Observe the behavior to find the apparent problem;

2.Observe collateral behavior to gain as much information as possible about the problem;

TROUBLESHOOTING 9-3