HP all in one/ printer jamed?

[Gogandantes]

ive got an hp printer/scanner all in one. its not allowing me to use any function on it because it says paper jan. i have opened the back door & theres no paper at all no tiny pieces or anything i can see. just before that it made grinding noise that was terrible. looking in the back i can see when i hit print the back rollers do not turn. they move just slightly as if they cant rotate all the way around assuming they do a fulll turn normally. any help?

 

[S0ULphIRE]

Could be the gears are worn or broken inside. If it's in warranty still then send it in. If not, then you'll have to open it up and check yourself :/ that can be quite tricky unfortunately, printers generally are put together in an extremely un-user-friendly way.
If it has a drum or toner unit make sure you take them out and check for bits of paper too. What model do you have?