Still getting info on this from from another tech. All I know so far is the system is a Nortel. I suspect a MICS or BCM 50 (not my customer, yet).

Customer just switched from copper lines to fiber from the under- build company, and now the system won't ring. Tech measured 47 volts incoming, which won't ring the system. After bumping up to 52 volts, then the system does ring. Are these line cards that sensitive?

Thanks.
Jim