Analog issue, which is a mystery

[mojoputter]

S8500 CM 3.1.5
Have a cabinet connected to the S8500 thats probably at least 20 years old, System 75 stickers on the back.

For some reason the cabinet loses power for just a second and all the analog cards on carrier B,C,D and E need to be pull out to bring them back on-line. All the digital boards work just fine on all carriers. Carrier A is never affected by any of the issues, analog and digital card are not affected by this mysterious issue on carrier A.

Now if we power down the cabinet and power it back up we don't have to pull the cards, everything comes up fine after powering down then back up, and this seems to be easier and quicker get dial tone.

When we display alarms, all thats there is AC-Power + Power alarms, so we have replaced the power supply, and then an hour after we replaced the PW supply, it burped again and all the analog boards had no dial tone except carrier A.

I'm thinking now it could be a carrier PW supply but we never see any carrier PW alarms.

One other thing, this did not start happening until we replaced the S8500 with a refurbished S8500. I don't think it would have anything to do with that because the S8500 never shows any alarms or resets, and the cabinet and S8500 are powered off the same UPS, different circuits though.

I don't have much expirience with these older cabinets so if anyone has any idea what this could be your help would be appreciated.
We have replaced the power supply and batteries

 

[AvayaTier3]

what are the analog board types and how many in each carrier?

A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"

bsh

36 years Bell, AT&T, Lucent, Avaya
Tier 3 for 26 years and counting

http://bshtele.com

 

[mojoputter]

The board types are TN742.

Carrier A has 9 TN742's
Carrier B has 7
Carrier C has 18
Carrier D has 17
Carrier E has 12
Hardware vintages vary from 10 - 19

 

[mojoputter]

.

 

[AvayaTier3]

If you have UPS on the cabinet, you do not need the batteries and 397 charger. These provide nominal holdover:
up to 10 minutes for carrier A, and only 10 seconds on the other carriers.

You can disconnect one battery, then unplug the cable that goes into the back of the 397 battery charger.

test environment will abort test 5 but that just means it's not going to give you POWER alarms due to battery issues any longer.

If you continue to have issues, I also suspect power.

A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"

bsh

36 years Bell, AT&T, Lucent, Avaya
Tier 3 for 26 years and counting

http://bshtele.com