A: Check power supply voltage at intercom is 23.4v DC or more. Cable length from PSU to intercom should be less than 25 feet and in 14 gauge for longer distances. See guide. Check the fuse.

A: This means the unit is not able to detect the network for some reason.

• Power off the unit, remove the SIM and check it in a mobile phone to verify it can make a call and has calling credit if it is a Pay As You Go SIM.
• Disable any PIN code request if active on the SIM card.
• Check the SIM is a standard voice capable SIM. If you are unsure, contact your SIM card provider to verify.
• Check the reception is medium or good. Poor reception is not sufficient.
• Power off, remove the SIM, use fine sand paper to lightly sand the SIM pads and contacts on the GSM unit, lightly bend the contacts upwards so that they make better contact with the SIM and try again.
• Check antenna is connected and does not have too many sharp bends on the antenna cable.
• Check the height of the antenna and make sure it is not inside a metal enclosure.
• Check correct power cable size for cable length from PSU. Refer to manual for guidelines

A: If your number is a private or number withheld, then it will not work.

• Ensure the number is programmed as you would normally dial it from another phone.
• Ensure you have adequate GSM signal at the intercom by sending *20# as a text.