sundance-communications.com/forum Forums General General Telephone & Systems Information ARRIS Cable Equippment burning out circuit cards

Has anyone else had a problem with high current from an Arris cable equipment box that give dial tones from bandwidth?

I have a Samsung DCS 50 that ran perfectly well for over 9 years until they switched to Time Warner that uses Arris bandwidth to analog (sic) dial tones. About a month after switching, they had no dial tone and I replaced two 6 CO dial tone cards. About a month later I again replaced two 6 CO dial tone cards and Time Warner said it could not be their problem of course.

So far I have replaced 9 dial tone cards and they said they swapped out the equipment when I wasn't there.

While my case is specific to Samsung I posted this here because if if happened to one kind of system it probably happened to other systems.

Thanks, Bracha

Never had a problem with Arris

Easy enough to check the loop current. I've never heard of such a problem though.

-Hal

You may have to ask the customer to baby sit the system and check the loop current while there. Had a similar situation a few months ago on an EarthLink Adtran. Didn't blow up the cards on the nec aspire, but all calls were being dropped at once periodically. I was able to prove it was not the aspire, but not the direct cause from EarthLink as I suspected after the fact it might be loop current. Magically, the problem went away in its own. Hmmmmm.

I haven't had any trouble with Arris from Mediacom around here. But years ago I had one Nortel MICS system on Windstream POTS lines, about two blocks from the CO. Started going thru line cards all of a sudden. Sometimes monthly, sometimes every 6 months. Strangely, the loop current was ok.

I tried everything from programming the system for a short CO loop, adding resistors in front of the ksu, using loop current limiters from Sandman, and changing/adding grounding. I'm not sure what finally fixed it. I think the grounding and loop current limiters had a lot to do with it. The last several years, the building has become part of another larger system with no service directly to the problem building.

Jim

I assure you that grounding has nothing to do with correcting these issues. More grounding actually invites more problems.

Fake dial tone devices often are not regulated by the FCC with regard to Bellcore (Telecordia) guidelines. They also operate under notoriously low line voltages, far outside of these specs. I'd check the line voltage AND off-hook loop current. If the voltage isn't in the area of 48 volts and the loop current between 27 and 35 mA, then the service provider needs to correct this.

That becomes the big issue. Getting them to understand and more importantly, to know how to fix it.

You, most definitely, have a loop current problem. Measure the loop current. As Ed wrote, it needs to be between 25-35 ma. i had a Comcast Arris box delivering as much as 60 ma of current. Most likely, the cable company will be of little or no help. In fact, their technicians will probably know nothing about line current. To remedy the problem, visit Sandman for current regulators.

Rcaman

Thank you so much, he is now moving to VOIP phones, No bad cards for over 9 years then 9 bad cards on Arris in about four months.

Thanks for the replies, Bracha

Yea, voip will cure everything *sic*. I do have another thought though. We already know that high loop current can damage a system and we know how to measure if the lines are high. Has anyone ever heard of loop current spiking periodically then returning to normal? I had that thought on the job I posted above. Measurements tested normal with a multi meter but when the meter was removed after that testing, calls would be dropped randomly during the day. As part of my testing, I stole one line off the phone system and connected it to an analog phone. When all calls were dropped off the system, the analog phone went quiet for several seconds, but the call it was on did not drop. It came back. The Adtran did not appear to reset during this.
Thoughts anyone?

Years ago, when we serviced a large PBX at a coal mine, all the trunks were supplied via SLiC 96. We were getting reports of intermittent dropped calls and sizzling on the call. We must have dispatched 20 times and found everything normal.

Then one day, I was at the site and on the phone when it happened to me. I also noticed that all the lights dimmed at the same time. It turned out that there was a bad leg off the power company feed going to the SLiC 96 and was sending a huge voltage spike into everything connected to that phase. It happened, usually, when they cranked up the main feeder belt to the prep plant. There were some 1,000 hp. motors that would start up in sequence. The plant engineer figured out that when the one motor was almost up to speed, another would kick in before the first was completely up to speed. The tests revealed that when this happened, the resulting huge current draw and the flaky phase would cause a really nasty current and voltage spike, but just on that one phase. The SLiC, unfortunately was on that phase.

So, I measured the line current when the event occurred. I measured over 100 ma. across the tip and ring. Bell Atlantic (that was the name before Verizon) was constantly at that SLiC changing out power supply modules and batteries. When it was finally determined that it was a problem on the phase, the mine electricians moved the SLiC to a good phase. That solved the "great mystery."

Rcaman