Our office hummed along contentedly incongruously so what with the
glowering sky above, and the oppressive, sweltering air just beyond our walls. Yet there
we were, isolated in our air-conditioned splendor, unaware that disaster was about to
It lasted only a second or two. A lapse of power. So brief. So
hesitant. But so
ruinous for harm may steal upon us, all stealth, particularly when it emerges from
some ozone-swathed realm.
While so brief a power outage may sound innocuous, a two-second lapse is actually worse
that a power outage lasting several minutes, at least as far as computer equipment is
concerned. Any computer equipment, including monitors and printers and other peripherals,
will most likely be sitting there, painfully vulnerable, their switches still in the ON
position, when the power returns. The problem, you see, is that when the power comes back
on, it will often burst through in a dangerously strong surge. (Oh, cant you just
hear the delicate sizzle of overloaded circuitry?)
Concerned about our servers as well as our phone system, I immediately went to check
their status. I knew all of our vital servers were hooked up to UPSs to protect them in
the event of a power failure, so I wasnt too concerned. First, I inspected our RAID
file server. No problem there. Then, I checked our phone system, which is an Artisoft
PC-PBX. To my dismay, I found the system in the middle of a reboot. I glared at the UPS
connected to the Artisoft PC-PBX. Oh, treachery, thy name is UPS! I howled,
savagely kicking the squat box.
I soon regretted my outburst. As it turned out, the UPS was almost certainly blameless.
It was nearly at maximum load. And how could that be? A little poking around revealed that
someone had actually connected another NT server to the UPS. Apparently, we had overloaded
the UPS, and thats what caused it to fail.
And the consequences? Well, the PC-PBX, unable to draw power from the UPS, went down,
its switch innocently in the ON position. Then, the power came back in a surge,
THE BEST LAID PLANS OF MICE AND MIS
We fully appreciated the importance of power protection, particularly with
respect to our phone system. We had made a point of connecting our PC-PBX to a UPS. And,
coincidentally, we had just committed ourselves to evaluating a couple of new UPS
products. The very week we experienced the power lapse (and surge), we had received Tripp
Lite and APC UPS products for our review. (APC sent me their Back-Pro UPS, which is great
for SOHO or personal computers, and Tripp Lite sent me the SmartPro 1250XL, which is
targeted at mission-critical servers.) Power protection, you may gather, was much on our
But as Ive just indicated, while we did take the trouble to install a UPS system,
we didnt take enough trouble to make sure we had installed it properly. This
realization gave me pause. What damage might our PC-PBX have suffered?
ASSESSING THE DAMAGE
Our PC-PBX, I noticed, booted successfully into Windows NT. Holding my breath, I checked
the Event Viewer just to make sure all the Services started properly. Everything looked
normal. Apparently we avoided a catastrophe. Pausing only to sigh with relief, I
disconnected our PC-PBX from the overloaded UPS and connected it to the Tripp Lite review
unit. (You may read the review of the Tripp Lite SmartPro 1250XL
in this issue, and the review of the APC Back-UPS Pro in the November issue of CTI.)
I was done. (Or so I thought.) I made a mental note to instruct our MIS staff on proper
UPS setup, and returned to my desk.
About five minutes later, I received a complaint that our phones werent ringing
on incoming calls. I immediately investigated, and determined that half of our 48 office
phones rang fine, but that the other half did not ring at all. My first thought was that
we had damaged one of our PC-PBXs telephony boards, a Dialogic MSI board. Each of
the two telephony boards is responsible for connecting the PC-PBX to 24 office extensions,
as well as providing ring voltage to these phones.
CALLING FOR HELP
I called our local VAR (which, incidentally, had done a fantastic job installing our
PC-PBX system). The VAR, DAC Systems, confirmed my suspicions that I had a blown Dialogic
MSI board. According to DAC Systems, Dialogic has encountered this no
ring-voltage problem with other installations.
Now that we had identified the source of our troubles, I contacted Artisoft, and
requested that they send us a new Dialogic MSI board. We received the board the next day.
PLAYING MR. FIX-IT
Since I figured I would need only five minutes to install the new board, I
decided to shut down our PC-PBX during lunchtime. I should point out that this was only
the second time we needed to shut down our Artisoft PC-PBX in the six months weve
used it. The first time we shut down the system, we took care of an unresponsive keyboard,
the problem being a faulty port on the console switcher to which the PC-PBX was connected.
While wearing an anti-static wrist strap (to reduce the risk of any static shocks), I
disconnected the power cord to the Alliance Systems industrial computer, which is where
the Dialogic cards resided. Before I could remove the damaged Dialogic MSI card, I needed
to disconnect another power cord. This second power cord, which connected directly to the
outside of the MSI board, was what carried the ring voltage to the board.
Once I had disconnected the power cords, I removed the damaged board and carefully
inserted the brand-new Dialogic board that I had received. I turned the system on, and
hoped for the best.
After booting into the system and checking to ensure that the Artisoft and Dialogic
services had started, I made some test phone calls. All the phones rang! Success, it
seemed, was at hand.
EVEN MR. FIX-IT CAN BE WRONG
My glee upon hearing the ringing of the phones soon turned to consternation when
it became clear we had another problem. Once the phones started ringing, they
wouldnt stop! Even if I hung up the phone on the dialing end, the phone on the
receiving end would ring and ring and ring, without pause. To stop the incessant ringing,
I had to pick up the handset on the ringing phone and then hang it up.
I thought to myself, Well, at least our employees will know when an incoming call
arrives. This cheering thought, however, soon faded as I began fuming about the new
board, which had proved to be faulty.
I had little time for fuming, however. Soon, I heard a chorus of complaints about the
non-stop ringing of the phones. By all accounts, the ringing was especially annoying when
it issued from an unattended cubicle. In such an instance, the phone would ring until
someone walked over and hung it up.
The consensus was that we would be better off if the phones didnt ring at all.
So, I reinstalled the original board. I observed ruefully that my five-minute triumph had
turned into a two-hour rout. And still no end was in sight!
Anyway, after I had reinstalled the original board, the other Dialogic MSI board
started to exhibit the same problem this boards phones wouldnt ring,
either. Now I had two malfunctioning Dialogic boards, which meant no ones office
extension would ring.
After fiddling with the board, running Dialogics diagnostic utility, and
rebooting several times, I was able to get one of the boards working again, and fully
functional. However, during the rebooting procedures, I noticed that the semi-functional
board was, well, a bit flaky. Sometimes it worked, and sometimes it didnt. So, I
decided to order two new Dialogic MSI boards, just to be safe. I contacted Artisoft again,
and they responded by sending two new Dialogic MSI boards via an overnight service.
OUT OF THE BLUE A BOLT OF BLUE
This time, rather than working on the Dialogic boards during work hours, I
decided to come in on a Sunday, when incoming phone traffic would be minimal. Then, I
would be free to pull out both Dialogic boards and replace them with the new boards
Artisoft had sent me.
While pulling out one of the faulty boards, I saw a blue arc of electric current, half
an inch long, pass between the two boards! Since the boards were so close together, a
soldering pin on one of the boards must have touched the other board. Well, I
thought to myself, if it wasnt broken before, its definitely broken
now! I had that odd, giddy sensation you sometimes get when you think you may have
destroyed something expensive.
I wondered how such a large electric current could pass between the two boards. Static
electricity? No, the current seemed much too powerful for that. I checked the power cord
running into the industrial chassis, but it was disconnected. Then, I checked the external
power connector for the board I had removed. This connector had been removed. What was
left? I looked at the board that was still seated. Hmmm. This board still had its power
When I swapped boards, it didnt even occur to me that I would need to disconnect
the external power cord running to the Dialogic board still in the chassis. In all my
experience, which included the installation of many ISA and PCI cards, the precaution of
disconnecting the computers power cord was all that was necessary.
I also tried to be as careful as possible to make sure the board I was lifting
didnt touch the board next to it. Apparently, I wasnt careful enough, as the
bolt of blue current passing between the two boards would suggest. Fortunately, the boards
were already fried. I was certainly glad I hadnt damaged either of the new boards!
I should point out that I didnt think that the power running into the Dialogic
board was active or live until I actually turned the PC on. I
figured some sort of relay on the Dialogic board itself would switch over and allow the
current to pass only when the PC was turned on. My guess was wrong.
I dont suppose Im the only person who would ever make such a guess.
Consequently, I would like to suggest to Dialogic that they include a Read Me
First! note that includes a warning about disconnecting any external power cords to
any Dialogic boards already residing in a chassis.
THE APOTHEOSIS OF MR. FIX-IT
After installing both the new boards, I reconnected all the power cords and
turned the system on. The result? Now, not only did the phones fail to ring, but I
couldnt get dialtone on any of the 48 extensions. Things had just gone from bad to
I found it highly unlikely that Artisoft sent me three bad Dialogic boards (one
originally, and then two more). To troubleshoot, I took out one of the new boards and put
one of the old ones back in. Now the new board worked flawlessly, and the old board was up
to its usual tricks of not ringing the phones.
Next, I decided to reinstall the new board I had just removed, just to see what would
happen. Granted, the two boards I now had in the chassis constituted the same pair I had
tried but 15 minutes earlier, and without success. However, my gut feeling was that this
combination was going to work. I rebooted the machine, and again made some test phone
calls. Success! All of the phones could ring! I even dialed a special extension, which is
set up to ring all the phones in the office. What did I hear? The ringing of every phone.
Music to my ears. You might even say the phones raised a fanfare, in celebration of an MIS
THE LESSONS LEARNED
So, what did I learn?
- Check the load on your UPS. Make sure you arent overloading it.
- Test your UPS. Unplug it and see how it handles the power outage, and see how long the
- Test your UPSs battery. A good time to check your battery is when you reset your
clocks to account for Daylight Savings Time.
- Dialogic has an excellent return policy. Lifetime guarantee on their boards, no charge!
(Except for the cost of shipping the board back.)
- Disconnect any external power sources to any telephony boards. Blue arcs look pretty
cool, but trust me, theyre not worth it.
- Respect Murphys Law. If something can go wrong, it will, and at the worse time
until you factor in Toms Law. (See below.)
- Take heart, Toms Law may save you yet. Throughout the history of TMC Labs and my
days working in MIS, I was wont to hear a colleague exclaim, Tom, it wasnt
working before. But then, as soon as you came by without even doing anything
it started working! Creepy, isnt it?
Dont ask me to explain it, just trust me on this one. Murphys Law and
Toms Law are actually mutually exclusive, but fortunately, in this case, Toms
Law won out, and I was able to get the new Dialogic boards working.
If youve had similar problems with the Dialogic MSI board or would like to share
your telephony board installation experiences or nightmares, I would love to hear from
Tom Keating is chief technical officer and executive technology editor for TMC. He
welcomes your feedback. To contact him, send your e-mail to Tom Keating .