I cant send a fax or reseave one - HP LaserJet 3030 All-In-One Printer

Make sure you have a dial tone.
Plug a phone in the wall to check( using the same cord. Then plug cord going from wall into "tel line" and check fax mode if you have a dial tone.
I don't think the 2, or 4conducter cord matters since the split out the same way

Sir/Madam

Solution one: Check the fax connections Use the following steps to check the physical connections, and then use the HP Fax Test Service.

Step one: Check the physical connections

1. Disconnect the telephone cord from the HP fax product, and then examine the connector on the end of the cord. Make sure that the cord has only two wires. Figure 1: Two-wire telephone cord
   
   

1. Four-wire telephone cordGraphic: Four-wire telephone cordIf the cord has four wires, replace it with a two-wire phone cord.
   If you must use a cord with four wires, use the converter that shipped with product. The converter allows a cord with four wires to work with a device that requires a cord with two wires.
2. Connect one end of the telephone cord to the telephone jack, and then connect the other end of the cord to the port labeled 1-Line on the back of the HP fax product.
   Figure 3: Fax only
   
   
   

1. 1 - Telephone jack2 - Two-wire telephone cord to 1-Line
2. Connect a single-line telephone to the 2-Ext port on the back of the HP fax product.
   Figure 4: Fax and telephon
   
   
   
3. 1 - Telephone jack2 - Two-wire telephone cord to 1-Line
4. Connect a single-line telephone to the 2-Ext port on the back of the HP fax product.
   Figure 4: Fax and telephone