Most of us would probably use the CLI TTY interface. As stated above. Plug into the TN port at the woring frame. The wiring would be correct there as it wouldn't have been changed.
From the command line in LD 32, key in e.g. stat TN, which is the port number and not the DN number. You can find the port (TN) number either from the UCM or CLI via e.g.
LD 20
REQ: PRT
TYPE DNB
CUST 0
DN xxxx
Press return until you see the line of details.
In LD 32 (or even LD 20) key in e.g. STAT 004 0 01 14 (What ever the TN is?)
then if it states DSBL, you know it's disabled, or IDLE if it's free and not used.
I tend to always do DISU (TN) to fully disable it again, before I do ENLU (TN) to enable it again. Use STAT (TN) to confirm the port status. If it's IDLE, then try IDU (TN). If you get a few lines of data, then it's plugged in.
Finally, key in FSUM ALL. I've been caught out recently with M3905 problems and that was due to a firmware download mismatch. This command will tell you what the firmware levels are and you may need to update some of the phones. Use FSUM to list out what the Call Server has and it will also tell you how many sets need changing.
All the best
Firebird Scrambler
Meridian 1 / Succession and BCM / Norstar Programmer in the UK
If it's working, then leave it alone!.