Hi, I'm Matthew and I'd be glad to assist you.
You don't necessarily need a dedicated fax line. You can run the fax on an existing phone line with the right settings.
There are 3 reception settings on the machine: Telephone priority, fax priority and fax only. The first 2 are designed for a shared line. If the machine is set to telephone priority, however, you have to manually receive a fax... It won't on its own. Fax priority will automatically receive faxes but will take priority over the phone line. But you can change the ring to answer settings on the machine to adjust how soon the fax picks up.
There is a distinctive ring setting on the machine, as well... But the distinctive ring would have to be setup through the phone company.
A very helpful link is http://usa.canon.com/cusa/consumer/products/printers_multifunction/office_all_in_one_inkjet_printers/pixma_mx870#Fax_Help
If you click "fax help", then select "help me choose the right setup mode and connection method." I hope this isn't the same link you've looked at, but it will walk you throught the setup procedure step-by-step.
I switched the chat to a Q&A session... So, I will be notified by email as soon as I get a response from you. Please let me know if you need further assistance with your fax settings and I'll be back with you as soon as I can. Thanks.
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Well, if you have a dedicated fax line you would not need a phone connected to the MX870. You can just plug the machine into the wall jack and set the fax on "fax only." Are you getting a dedicated line? I don't think you'll necessarily have to have a phone connected to the machine at all unless you want to set the machine to "Telephone priority."
Well, It might just be a matter of Comcast not offering the distinctive ring service. The machine is capable of using a distinctive ring.
Yes... Connect a phone to the fax machine. Then, confirm the machine is set to "Tel Priority". To do so, follow these steps.
(1) Press the FAX button.
The fax standby screen will appear.
Confirm the current receive mode (A).
(2) Press the center Function button.
The Receive mode settings screen will appear.
(3) Select a receive mode, and press the OK button.
To receive a fax when in "Tel Priority mode" when the light is flashing:
You can set the machine to "Fax Priority Mode" as well... The machine will then automatically receive faxes but could possibly interfere with the phone line. Follow the same steps as above to select this setting.
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