I'm bringing this back up because we have a customer with the same situation. This one is using 3.5 and we've already addressed the usual suspect areas with timers, etc. Customer has four lines, two tenants. Customer #1 is using lines 1,2 and 3. Customer #2 only has one line, #4. Cox is the service provider.

Calls on lines 1-3 drop randomly with no rhyme or reason. Short or long, they just drop and we've witnessed them happening. The problem is that this blasted system insists upon battery being present on the line ports or it will drop/deny access. I can't find any way for it to just look at a CO port on a 'dry' basis. PGM 160, B14 doesn't help. I think that if we could find a way for the system to allow access to CO ports without battery present, we wouldn't have this problem.

Calls on line 4 (on the expansion card obviously) don't drop.

The first three lines are on one COX EMTA and the fourth is on a separate EMTA (separate billing accounts). All four lines measure roughly 49.4 volts, which really surprised me.

We made Cox replace the EMTA for lines 1-3 today, and they did so without any issues. Within an hour of leaving, we received word that calls were still dropping.

We returned and flip-flopped the lines and button mapping, so that the lines 1-3 that are dropping are now on CO ports 4-6. We put the tenant's fourth line on CO port 1. Within an hour, he called and said that he's now dropping calls. With this said, it is clear that the CO ports 1-3 are bad on the base KSU.

I get that, but THREE CO line ports all failing for the exact reason at the same time? I can't use the loop current argument since the original three lines that are on ports 4-6 are behaving fine. I'm stumped and the customer is getting tired of this. Any ideas?

Ed Vaughn, MBSWWYPBX