02-04-2009, 05:21 AM
| | Re: Fax cable
> sherwin dubren wrote:
>> My c7280 all in one fax came with a 2 to 4 wire adapter for the phone
>> connection. I think it is designed to adapt 4 wire phone wire to the
>> 2 wire jack of the fax phone line. HP included their own 2 wire cable
>> that seems to reverse the connections of tip and ring. What is the
>> purpose of this reversal? My extra long 4 wire phone wire will only
>> work with the fax if it is connected through this adapter. Are faxes
>> wired differently from telephones?
>> HP is being nasty in not replacing my broken 2 to 4 wire adapter,
>> although my HP unit is still under the 1 year warranty. This wire
>> adapter is not shown in the accompanying HP documentation, but it
>> was included in the orginal box of accessories. HP will not honor
>> the warranty on this item. Makes me think twice about buying another
>> HP product. The HP provided phone wire is not long enough for me,
>> being 9 feet long. I need about 12 feet, hence the need for a
>> plain 2 wire phone cable and the adapter.
> I could be wrong about this, but I believe makers of fax machines
> might expect users to have more than one phone line at the place of use.
> Typical four wire phone cable uses red and green for the first line and
> yellow and black for the second line. Makers of fax machines might
> provide an adapter to connect to make the connection to the other line.
> It is unlikely that the tip and ring are reversed, but more likely
> that they are connecting to the other pair. If the fax machine has a
> two pin connector and you have a cable that will connect to it, you
> should be able to hard wire the other end to the terminal strip inside
> the wall connector. The same would be true if it had a four wire
> connector. Plug in the cable and try hard wiring the other end to the
> wall jack terminal strip once the cover is removed. If it does not work
> with matching the colors that are there, reverse them.
I have just one phone jack near the computer and fax machine. It is
sharing this connection with an answering machine and dialup modem, so
I don't want to rewire the phone connector at the wall.
I am still curious if the requirement to swap tip and ring at the HP
fax machine is peculiar to them, or do all fax machines do this
reversal. Anotherwords, why is the fax machine wired differently from
any phone device like a modem, telephone, etc.