Had a weird output on system monitor accompanied by no extension power on control unit.
System Monitor manual suggests other PRN codes are expected to be received instead of this.
Logic may suggest a problem with BD 1.1 and BD 1.8 or port 1.4 or port 1.8
Removed leads and cold started to no avail.
1: DS 8 PRI
2: DS 8 BRI
3: ATM combo.
Preferred running embedded.
PRI, DS 16 and 30 still online
Cold started system.
Ports all showed as available but unplugged in system status.
Removed all patch leads from DS on control unit.
Upgraded system and recreated SD (no need in the end)
Went through and isolated cards.
Caused by a blown component in Combo card pulling all control unit ports down.
Replaced with DS 8 in slot 3.