Paper jam error 1

SOURCE: "Clear paper jam" error, but there is no jam!

Thanks, tried all the maintenance options including cleaning the rollers. What I have found worked very well was to bin the printer and purchase an HP model!

SOURCE: Paper Jam

I have just had the same problem on one of these Canon MF4150 machines.
The manufactures warranty on our machine had expired just one week before this happened so I had to fix this myself.
The problem we had (which is very likely to be the same cause as yours) is when we removed some torn jammed paper, it had somehow pulled off a spring from inside the machine. The spring was linked to the paper jam sensor.
It does involve a LOT of work to fix it, and unless you are very 'techy' it may be quite a difficult task to do this for the 'average' person.
I had to completely disassemble the machine: Take off the front first (lift up the cover and there is 2 screws at the front and 2 clips on the bottom of the machine) Then remove the 2sides and finally the top (screws should be easy to see, to get the sides off, un-clip along the front edges and gently move them outwards and slide them backwards to release the clips on the back) being careful with the wires going to the scanner part). Then look for the fuser unit which is near the top at the back, there is a black rounded cover over the fuser. To remove the cover, look for 2 small clips one at each side and unclip the cover and gently lift upwards.  Under the cover on the left side you will see a small plastic rod which goes from the left side to a small tab in the middle, if you look about half way along that rod you should see a tiny spring, make sure this is clipped on properly and that you are able to rotate the rod and it should spring back to the proper position when you let go.
Once this is done, put it all back together again and it should work fine.

I'm sure a lot of other people probably have this same problem too so I hope this helps someone.

SOURCE: I have a Canon Pixma

It was covered by Staples Extended warrantee and they exchanged it.

SOURCE: I have a Canon MP470 that pulls 1/2 sheet paper and then jams

Paper feed roller
cleaning
When paper does not feed
properly.
To clean the paper feed
Machine button

SOURCE: We have a Canon Image Class MF3240

The problem is on the computer, not on the printer.

"A4" is a paper size, just like "Letter" and "Legal".

You probably have your software application, such as Excel, Word, etc., set to paper size = A4.

Do this in your program on the computer:
[File]
[Page Setup]
[Size] "8 1/2 x 11"

... and print your document again.