My Canon MMP780 multifunction printe: error #356 - Any ideas!!

First things first. Try and print report from the fax. Any kind of report. If it is printing OK, then the next step is to check if:

Your clients receive your faxes OK? If they are dark as well, then your scanner head is at fault.

When you make Copy on your fax and it prints dark it could be simply set with dark settings _or_because of the white calibration strip or roller being soiled or dirty, which acts as the ultimate white reference point for scanner _or_ the Scanner CCD sensor is in paper jam release position (too far away from reading the originals) just pull it back to normal feed position.

Or simply faulty scanner.

my dear you chek paper motor pic lift

I went online and found the HP8600 user manual and this is their solution to the error code 363 that you reported, which I copied off their site. Hope this works for you:

• Turn Error Correction Mode (ECM) off, if you encounter the same error repeatedly. Click this link HP All-in-One and Fax Products for more information on enabling or disabling ECM.
  

  
  

  NOTE: Error codes that apply specifically to ECM have ECM listed next to them.
  

  
  

Error Code: 356, 357, 358, 359, 360, 361, 362 ECM, 363 ECM, 364 ECM, 365 ECM, 366 ECM

Definitions

• The remote user pressed the Stop key, causing the session to be terminated.
• The remote machine encountered a system problem such as no paper or a paper jam. This prevented the fax from receiving any more pages, and caused it to terminate the session prematurely.
• The call-waiting service can cause this error. The click, heard for an incoming call, is actually a momentary disconnect of the line.
• The remote machine encountered an incompatible feature causing it to terminate the session.

Solutions

• Configure the remote machine for document reception by clearing any paper jams, loading sufficient paper, and clearing any other error messages.
• Configure the local fax machine to use a slower reception speed.
• Enable or disable the ECM setting.

I use to have an HP All-In-One Laser Jet printer that, for reasons unknown to me, wouldn't print after clearing a paper jam until I replaced the ink cartridge.

You could be out of toner = new toner cartridge.
You could be out of paper = reload paper
You could have a printer problem, paper jam, door open, etc

get the printer part working.

does it print a report if you press the 'report' key?

Incoming faxes automatically go into memory. We can't print them out. Would like incoming faxes to print out as they used to. have tried the on off button but it didn't fix the problem

You can download the user manual for this, just go to this link http://download.canon.it/manuali_operatore/files/L800ugen.pdf

look at the paper tray,some of your sensor are jammed,try tyo find out where is the sensor on paper try

The alarm sounds for only 5 seconds.When you receive a fax and the paper jams, the fax will be received into memory. When it has finished receiving the fax, the alarm will sound momentarily. When you remove the jammed paper, the fax will print automatically.

Please check rear door area for paper, can you use manual feed slot? Power off machine with all jams removed and paper loaded, then power on, can you tell us exact error message/lights that are shown in this state?