atcomsystems.ca/forum Forums TDM Business Telephone Systems Comdial Telephones & Systems DX120 PRI problem

You can read info about your circuit with the adtran installed. Any errors and which side they come from!

I'm not at all convinced it's F22/F.07 but go ahead and load F20/F.03. If it still acts up then there's only 2 likely things that it can be, faulty cabinet/PRI card or the LEC.

Did the LEC loop up the smartjack? I've had them tell me there's no errors but when I have them loopback they find issues. Never ever trust anything they say.

Also make sure all of the posts are tight that are holding the CPU, PRI and voice mail cards. Run a ground between the cabinet and the smartjack. Check/replace the data cable between the PRI and smartjack. Make sure this cable isn't near a faulty lamp ballast. Check if the battery backup isn't momentarily switching causing spikes. The DX should be slave, B8ZS, ESF.

Keep us posted.

I don't know if the LEC has looped the smartjack, for sure. If they did, they did this after hours...and, yes, they are notorious for claiming "all good" on their side. I once was arguing (on a Executone) that is was their equipment because I had 2 T1 cards in 2 cabs that I was switching the suspected circuit back and forth and the failure followed the circuit. The LEC tech said they were looping to their SJ just fine...problem was I had the damn thing in my hand, out of the shelf!! Turns out they were testing the wrong circuit.

Next trip there, I'll ground the cab/SJ and replace cables. The UPS is 3 years old now. All posts are tight and cab is grounded well.


Switch has been stable since last Thursday so far.

Oh...and I'll get into the adtran as well...

Thanks for the help.

Pri went down again today. This time the carrier could see the D channel was down and is escalating the ticket to ATT who owns the smart jack. Should have an answer tomorrow as to who dropped the D channel...the DX or ATT.

Keep us updated but by all indications there's a circuit issue.

Tests come back clean on the carrier side. They looped all the way to the CSU. When the PRI went down earlier this week, they seen that the D channel dropped.

Question: The D channel is channel 24, correct? What problems might be caused if users have access to CH.24 of the PRI? If trunk 839 (PRI is 816-839)is in grp 1 and that is the grp the users have for the PRI, is this a problem?

So, the problem narrowed down is that the DX seems to be dropping the D channel.

I did confirm that a #5ESS is the switch in use by CO with no change outs since the circuit was put into service.

Thought I'd found the problem...during the software upgrade, ESF got changed to SF and I didn't catch this. However, last week I changed it to ESF via remote connection and confirmed the change actually took place. System failed the same way again today. Went 6 days with no failure, then "poof". I thought for sure the SF/ESF safu was the culprit but it works/fails in the exact same manner. Carrier was surprised the circuit worked at all with the SF setting.

Purchased a new card today, Vertical warranty is useless...want me to send the card in for repair.

Will update what happens post new PRI card install.

Update...

New card failed as well but this time right away. The circuit was up, no alarms on the card, none reported in PCBA and none on the carriers side and still, calls inbound would get no ring and just sit there without being dropped. Outbound calls worked fine.

Called Tech support, they had no idea so I had them send me F17, I installed it and the F03 PRI chip, installed the original F17 database, then outbound only calls failed with the phone sets reading "yellow alarm". However, no alarms on the card/carrier/PCBA. I installed the F05 chip in the PRI then outbound calls failed with "trk release". I thought this may be the F17/F05 not being compatible so I installed F20 and all works at this point but we have to wait to see if it will again fail.

At this point I think my CPM or cabinet is hosed in some way.