All external-incoming fax prints out a blank page, All internal-incoming fax no problem. Just the faxes from other business that's printing out blank..

SOURCE: Printing of incoming faxes

I have the same problem on my hp all-in-one. it looks like a staple went through the copier and it shows on incoming faxes as well...

SOURCE: Fax does not print a confirmation page.

Use Function 8 not 6 and use set to lock it in. Lawrence

SOURCE: DOES NOT PRINT INCOMING FAX- PAPER COMES OUT BLANK

Have you tried a new toner cartridge?

Did you pull the plastic tape on the cartridge?

SOURCE: Panasonic kx-f1100 fax prints and sends 1 page on 2 pgs- 2big!

I found the solution to my problem: Press Menu, Pound Key (#), 35 to set copy size, 36 to set fax size, press Start/Set, then use up/down arrows on right side of the machine to select 92%, 86%, 72%, or Off. Press Start/Set to select desired setting.
Press Menu to exit!

SOURCE: when faxing a 401 error is reported

error 401 means that your number is not programed in the machine you are trying to , so it blocks it