Take a look at the shelf itself and see if anything is plugged into the 3rd 8p8c jack on the NCTE mounting (SJ shelf). Those shelves can be wired out for handoff on a 25 pair block or the internal 8p8c jacks. A lot of the time vendors would just use the jacks instead wiring to the block.
Also, there is a dip switch that will change the handoff from an RJ48C (T1) to RJ48S (DS0). It should be configured as a RJ48C since the ADC Soneplex can only provide T1 service, but it might be worth seeing if you are able to tell how it is set.
