I have an OKI C3530 MFP that tells me to open the top cover due to a paper jam, but no paper anywhere. The machine was stopped in mid print and is now confused. Help!

SOURCE: Dell printer problem

Sounds like you may need to replace the pick up rollers on the machine.  Without knowing exactly where the jam error happens during the print process, it's hard to say.

SOURCE: Paper jam Brother MFC-215C

Thanks, your suggestion led me to the solution, the jam not in the rollers or a senser, but it's in the dock of the printer head, when the printer head moved across, I shone a torch into the dock and saw a black thing, so eventually pulled it and realised that it was paper and it had been dyed black by the ink so that's wht it would be hard to spot!!!! Thanks again

SOURCE: paper jam, open back cover, then remove paper jam

Remove the paper tray. Check that the paper length adjustment is set correctly for the paper you are using. It's the small blue dam at the center 'back' of the paper tray.

SOURCE: My Oki B4545 MFP alarm always on

Solution provided by printer manufacturer tech support which worked for me.
1. Open all doors (front & back)
2. Remove tonner
3. Turn off power
4. After 20 secs turn on power
5. Close back door
6. Insert toner
7. Close front door

Fixed now!

SOURCE: canon ir 2016 is displaying

there is a black switch knocked out of it's holder.