No phone dial tone

Make sure you have the phone line plugged in, also make sure it's plugged into the LINE port on the machine. (Ext. is for a extension, i.e. secondary phone for manual dialing)
Also check that the wall jack is functional too, easiest way to do this is hook up a regular phone to the jack and if you get a dial tone you know it's okay.

If the wall jack is getting a dial tone and the line is plugged into the LINE port you may have a bad phone cable, try a different one.

WHat model is the fax machine? Also check to make sure that the phone line and the fax line are not 2 different phone jacks. Also if the phoneline and fax line are on the same jack, make sure to program the fax number into the fax machine. Also, double check if the fax machine has an in and out phone jack that it is in the in jack.

I want to make sure I understand this completely. You get no dial tone from the fax machine when hooked up to VOIP. In the past, was there an audible dial tone from the fax, or did it just dial silently and give you an error if there was no tone? When you said you got a dial tone by connecting a phone to the ext phone port of "the machine" did you mean the fax machine? If you get a dial tone by running a phone through the fax machine, then the line is good. I have used a fax machine over Sunrocket before they went defunct, which used the same technology base as Vonage - so it should work. If you used to get an audible dial tone when using the fax, and no longer do, and you are geting a dial tone on a regular phone that is connected to the ext. port of the fax machine, then the problem has to be in the fax machine itself, not the VOIP. If you can verify that, we can go from there.

? Other equipment, which uses the same phone line as the HP All-in-One,
might be causing the test to fail. To find out if other equipment is causing a
problem, disconnect everything from the phone line, and then run the test
again. If the Dial Tone Detection Test passes without the other equipment,
then one or more pieces of the equipment is causing problems; try adding
them back one at a time and rerunning the test each time, until you identify
which piece of equipment is causing the problem.
? Try connecting a working phone and phone cord to the telephone wall jack
that you are using for the HP All-in-One and check for a dial tone. If you do
not hear a dial tone, contact your telephone company and have them check
the line.
? Make sure you have correctly connected the HP All-in-One to the telephone
wall jack. Using the phone cord supplied in the box with the HP All-in-One,
connect one end to your telephone wall jack, then connect the other end to
the port labeled 1-LINE on the back of the HP All-in-One.

If the supplied phone cord is not long enough, you can extend it. For
information, see The phone cord that came with my HP All-in-One is not long
enough.
Check the connection between the telephone wall jack and the HP All-in-One
to make sure the phone cord is secure.
Make sure you use the phone cord that came with the HP All-in-One. If you
do not use the supplied phone cord to connect from the telephone wall jack
to the HP All-in-One, you might not be able to send or receive faxes. After
you plug in the phone cord that came with the HP All-in-One, run the fax test
again.
If you are using a phone splitter, this can cause faxing problems. (A splitter is
a two-cord connector that plugs into a telephone wall jack.) Try removing the
splitter and connecting the HP All-in-One directly to the telephone wall jack.

If you are using a phone splitter, this can cause faxing problems. (A splitter is
a two-cord connector that plugs into a telephone wall jack.) Try removing the
splitter and connecting the HP All-in-One directly to the telephone wall jack.
If your telephone system is not using a standard dial tone, such as some
PBX systems, this might cause the test to fail. This will not cause a problem
sending or receiving faxes. Try sending or receiving a test fax.
Check to make sure the country/region setting is set appropriately for your
country/region. If the country/region setting is not set or is set incorrectly, the
test might fail and you might have problems sending and receiving faxes.
Make sure you connect the HP All-in-One to an analog phone line or you will
not be able to send or receive faxes. To check if your phone line is digital,
connect a regular analog phone to the line and listen for a dial tone. If you do
not hear a normal sounding dial tone, it might be a phone line set up for
digital phones. Connect the HP All-in-One to an analog phone line and try
sending or receiving a fax.
Make sure you use the phone cord that came with the HP All-in-One. If you
do not use the supplied phone cord to connect from the telephone wall jack
to the HP All-in-One, you might not be able to send or receive faxes. After
you plug in the phone cord that came with the HP All-in-One, run the fax test
again.
After you resolve any problems found, run the fax test again to make sure it
passes and the HP All-in-One is ready for faxing. If the Dial Tone Detection test
continues to fail, contact your telephone company and have them check the
phone line.

1. Make sure that you have plugged the phone cord directly and securely into the wall jack and into the back port of the fax product. The fax port on your product is marked "Line," "To Wall Jack," or with a wall jack symbol.
2. Make sure the Line Interface Unit (box that the phone cord plugs into) is fully seated into the back of the fax product.
3. Remove any other devices from the line such as splitters, credit card machines, or telephone answering machines.
4. Try sending and receiving faxes on a different fax line.
5. Try using a different telephone cord.
6. Have the phone company test your line for static or noise problems.
7. Turn Error Correction Mode (ECM) off, if you encounter the same error repeatedly.

Regards
Riztech

There is a problem either with the Line Interface Unit (LIU, also known as the fax/phone line connector) or the fax hardware, because the unit is having problems sending or receiving faxes. The unit may hang on "Initializing." This document explains how to troubleshoot the LIU and fax hardware. SOLUTION: Please perform the following: Front panel hangs on "Initializing"

1. Pull the power cord connector from the back of the base unit to recover from the error.
2. Unplug the LIU from the back of the ADF. It is located on the left side (facing it), and is where you plug in the telephone lines.
3. Plug the power cord back in, power it up, and see if it hangs without the LIU inserted.
4. If it does not hang without the LIU inserted, power the unit down, plug the LIU back in, and power it back up. If it hangs, the LIU is faulty.
5. If it does hang without the LIU attached, unplug the ADF from the base and see if it hangs. If it does, the base is faulty.

Testing the LIU The primary test for the LIU is whether or not you get a dial tone. Sometimes, you need to re-seat the phone line several times to get a good connection. If after trying the things below, there is still no dial tone, or initialization hangs, the LIU may need to be replaced.

1. Verify that the phone line is connected directly from the wall jack to the plug in the LIU that says "To Wall Jack."
2. Verify that the LIU is plugged securely into the product. If it is not, there will be a message at power-up saying the LIU is not connected. If it is, the date and time will display.
3. If the LIU was re-seated, cycle the power on the unit. The unit should display the date and time.
4. Unplug all other accessories, like a telephone answering machine or modem. If the LIU appears to work fine after unplugging them, these accessories may be interfering.
5. Place a document in the Automatic Document Feeder (ADF). The display will flash "Document Loaded."
6. Press Start Fax to verify there is a dial tone. If so, try sending a fax.
7. If there is not a dial tone, unplug the product from the wall jack, and plug in a regular telephone to verify there is a dial tone at the wall jack.
8. If there is no dial tone on the telephone, the wall jack or phone line may be faulty

You are describing a FAX modem failure. You need the fax board replaced in the printer.

You are NOT a ding dong!

These plugs can be confusing. If you are just going to use the machine to fax, then plug your phone line into the jack on the fax machine that looks like a wall jack and connect the other end to the wall jack on the wall. This is also called the "line" jack.

If you want to use a phone with the fax machine (if it isn't already equipped) then plug the jack in as described above and plug a phone into the jack that looks like a phone. Test for a dial tone.

The remaining jack applies if you want to connect your PC modem through the fax machine. Your PC (assuming you have one) may or may not have a modem.

Typically, a fax machine is connected directly to a telephone wall jack with a known working connection. Try plugging the fax machine directly into a wall jack first and pick up the handset on the fax machine if it has one. You should get a dial tone. Then try to fax something to someone you know.

The machine can also usually be routed through the modem in a computer by connecting the "line" cord on the modem to the wall jack and plugging the fax machine into the the "phone" jack on the modem. You may need to install the software that came with the fax machine to get this to work.

If you have no dial tone, check the wall jack with a known to be working single line phone. If there is a dial tone, it's something to do with fax machine, the computer modem or the connections.

Some fax machines can take advantage of internet faxing through a cable modem or DSL connection. Check your manual for the options available.

I would double check your phone cord. There is usually 2 jacks in the back of the fax machine. 1 is for Line, and 1 is for phone.
Your phone cord should be hooked up in the LINE jack that goes to the wall.
I would also double check your phone cord on another phone to make sure the cord is good.
If you look at the clear connector that you plug into your wall and fax machine, does it have 4 copper/gold color wires contacts imbedded in the clear plastic connector?

Another thing to try, if you fax machine has a Line and a Phone connector, try plugging in a phone in the PHONE connector. Then hook up another phone cord going from the LINE to the WALL jack.
If you get a dial tone on your Phone, then you know you have it connected correctly. If no dial tone, then I would go back to the phone cord.
check those things and get back to me and I will see if I can help you with more suggestions.
Good luck.
Mac =)