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Fax Machine Connection

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Member Since: ‎08-31-2007
Posts: 1
Message 1 of 5 (2,483 Views)

Fax Machine Connection

How do I connect my fax machine off my Comcast modem. I bought a DSL filter, need to know the correct wiring set-up.
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Regular Contributor
Member Since: ‎09-27-2006
Posts: 131
Message 2 of 5 (2,482 Views)

Re: Fax Machine Connection

You are wrong... the FAX machine is designed to work only on the phone line not on cable... it wouldn't work on the cable anywhere...
You should use the phone line to hook FAX machine up...
Posted by
Problem Solver

Member Since: ‎04-07-2005
Posts: 1,210
Message 3 of 5 (2,480 Views)

Re: Fax Machine Connection

Do you mean you have comcast digital voice?  If so you should be able to just plug right into the modem's phone jack (or any other phone jack that connects to it) without any filters.  DSL filters are only for DSL service.
Though I'm not positive if there are any issues with running fax via comcast's VOIP service.  I think it works fine.
Posted by
Email Expert

Member Since: ‎04-27-2004
Posts: 18,247
Message 4 of 5 (2,472 Views)

Re: Fax Machine Connection

Return the DSL filter, you don't need that with cable modems or VOIP service. As the name implies, it's only for DSL lines.

If you do actually have CDV, there's a sticky post Fax Troubleshooting for Comcast Digital Voice in the Comcast Digital Voice forum.
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Member Since: ‎08-10-2009
Posts: 2
Message 5 of 5 (2,424 Views)

Re: Fax Machine Connection

after searching for hours on the internet today I discovered a simple trick. Faxes only use the middle two pins(red and green)  of the newer 4 pins connectors. The outer two pins (yellow and black) create a host of problems including dropped faxes, communications errors and "phone off hook" messages. Disable the outer two and your fax will work like a charm plugged into the cable modem or using a splitter for the phone!