The following was adapted from an old magazine article (unknown source; please let me know if you know, anyone).
1. To Start:
• Is the problem system-wide or just one phone?
• If system-wide, check the phone system cabinet’s AC plug or the circuit breaker.
2. Phone Problems:
• Is your handset plugged in? Make sure that the handset cord is plugged into the handset and the base, and also that the connection between the phone base and wall jack is secure on both ends.
• Does your handset sound “crackly?” Is the handset cord frayed or damaged? Can you replace it with a new one? Does that make any difference?
• If you hear static, tap your mouthpiece. This may fix the problem. Or you can replace it with another handset to see if the handset has gone bad.
• Is the phone forwarded?
• Did someone spill soda or coffee on the phone? Break the offender’s fingers. Dry the phone and clean it. Good luck.
• Do you have a spare phone? Can you unplug the troublesome phone and plug a new one in (or one that you know works)?
• Check all your phone’s feature buttons-like Monitor or Do Not Disturb. Maybe your “Do Not Disturb” is not letting you get any calls?
• Check the volume control and ringer setting. Did you switch your ringer off, or have you turned it down too far?
3. Console Problems:
• Is it still in Night Service?
• Are the date and time correct on the system? If not, the automatic schedule will also be changing at the wrong time.
• Is your headset or handset plugged in? Make sure it is plugged in all the way. Have you plugged a broken handset or headset in? Does the headset use batteries, and if so are they fresh?
• Has your operator been trained on the console? Does he/she know how to use it?
4. Line Problems:
• Run next door and see if their phones are working. Maybe your dialtone provider’s central office is down or the phone company has lost a major feeder cable in the street?
• By calling your lines on a regular basis, you can tell quickly if the line is bad, semi-bad, or your phone system is having problems. You can do this by “feel” as you get to know your phone system better.
• Do intercom (inter-office) calls work? Do local calls work? Do long-distance calls work? Check. There can be different vendors for each, so it’s not uncommon to see different qualities of service. Knowing the exact situation will help you tell which vendor may be at fault.
• If you can’t hear on some long-distance calls, but can on others, it’s probably your long-distance carrier. There’s not much you–or anyone else–can do, other than change carriers or buy yourself a handset amplifier.
5. System Problems:
• Look at your main switch. Is water dripping from the floor above? If any water is anywhere, kill your circuit breaker instantly and declare a holiday. You can dry off a wet PBX and get it running again. But if you run power to it while it’s wet, you will short it, blow it, pop components on it and generally just destroy it. Holidays are more fun. P.S. When you turn it off, put something on it to stop the water, like a plastic sheet, etc.
• Plug a lamp or other small device into the surge protector between your wall outlet and your PBX. Does the light work? Or is the surge protector blown? If it is blown, get another surge protector immediately.
• Is the phone system plugged into a UPS (Uninterruptible Power Supply; AKA battery backup)? These do go bad and can make phone systems go down or act very weird. Try plugging the phone system directly into the wall to see if it starts behaving.
• What did your cleaning person do last night? Which plug did he knock out? Which connector did he fill with soapy, dirty water? Check the quality of the wax he used on your floors. It really doesn’t wax eloquently in your phone system.
• Has someone plugged anything else into the same circuit as your phone system-like a computer, vacuum cleaner, refrigerator, or something else with a motor? Get rid of it instantly.
• Did a telephone serviceman just visit you? Did he destroy one thing while fixing another? Get the last technician to tell you what he/she did and make some guesses on what might now be wrong. It’s the technician’s responsibility to fix anything he/she has broken.
• Is anything blocking your phone system’s vents? 300 yellow page directories? Or six tons of xerox paper? Phone system rooms are rooms to put phone systems in. They are not storage areas.
• Wait until everyone’s off the phone. Turn your phone system off, count to twenty, and then turn it on. This is called re-setting the system. It clears it, just as re-booting a computer clears the bugs out of it. It may take several minutes for the system to finish booting up.
6. Nothing worked?
• Well, you tried. It’s not always possible to avoid a service call.