We cannot receive or send faxes

I suggest You Go to Official Canon Printer Page For You Canon Printer Problem On Below Canon forum URL Link: If You Cannot Receive Fax MF8350Cdn MF8050Cn In Case You Still face Problem and Need Online Assistance Then Please Follow Us For On : Canon Printer Support

First check the phone line it is ok,second try to put another printer with fax on that line and try to look if is work the fax.Fax board may be defective,try to change the fax board.

power you printer on
check for dial tone
if it is not coming then contact your fax connection provider.

You have to cancel the fax. If its saying that then the paper sent to you was a legal sixe 8.5x14 and needs that type paper to receive the fax. Some faxes have legal trays and A4 but most don't.

It means No Good. 5 possibilities:

Receiving machine unplugged
Not a fax number
Wrong fax number
Busy signal
Digital Phone Line

Check out the Easy Setup Instructions available here. If you can neither send nor receive faxes, you may not have the phone line connected to the correct port, see page 34 of the guide. Also check what receive mode the machine is set for. Pages 42 and 43 explain the different options and how to change the receive mode.

Hello. Please make sure your telephone line is plugged into the correct outlet.

Most fax machines typically allow you to plug the line (the cord that goes from the fax machine to the wall jack) and and a telephone (the telephone connects to the fax machine).

In order to fax correctly, you must plug the line into the jack with a block (looks like a 'T') marked on it. Do not plug the line into the jack marked with a phone hand set marked on it.

http://gdlp01.c-wss.com/gds/0900002546/PIXMA_MP780_750_Easy_Setup_Instructions_EN.pdf

This shoulds in detail how to connect the line properly. For this printer the line cord must be plugged into the jack labelled "L"

http://gdlp01.c-wss.com/gds/0900002542/PIXMA_MP750_780_Quick_Start_Guide_EN.pdf
This will show you how to actually send the fax. On your PDF View select page 42.

Have you check when you dial the no. its working?? Is it any dialtone problem in fax..
Check the phone line connect to the printer fax connector properly and having pulse.

Yup, MP780 BSOD's everytime I try to print to its fax.