No response from the modem Check your physical serial connection.
Does the PC/cable combination work on other modems?
Is it the correct cable? (cf. 11.4)
Is the cable grounding connected correctly (floating ground)?
Check cable.
Check your baud rate, COM1, COM2, etc configuration on the
PC (cf. 7.1).
Try typing which is XON and ECHO to re-enable
communication to LTUs occasionally left in XOFF state
Try selecting the modem using %n, n being modem address.