we have problem with WorkCentre 3550. We called support for assistance and for 2 times they changed fax card, so the machine is almost new... But still the fax doesn't work! We think now that could be a telephone line problem. What kind of line does the 3550 support? Is it digital or analogic?
Only supports analog line. Please make sure it is a real analog line and there is no converter from digital to analog. If you have a converter then you need to decrease the fax speed to 9600.
If you have any analog phone, just connect it to that line and do a call. Try to call to a fax number and check if is answered. If yes, you should have no issues with your device.
Still not working... we called assistance and during telephone conversation we colud send just one fax and then again the same problem! We checked telephone line, it's analogic, we cannot find any solution yet. What about fax speed? Where i can find this option?
If you have a poor line, decreasing the speed could solve, but, if I'm not mistaken, this only can be done by a technician. You have to call for one.
In the meantime, try other thing. Follow this procedure, find the ECM Mode. Turn it Off. This will turn off the error correction. This is only a test and it should be on, but if your line is really poor, the errors are so many that the device can't send a fax because is always trying to correct the errors.