Our canon GP160 is not working properly it is not a paper jam on the display screen it is just saying "check printer" and the error button is flashing red? it wont let us copy anything we have tried switching it on and off.

SOURCE: Lexmark E232

oh my GOD ,PLESE OPEN ITS ELECTRONIC BOARD AND REINSTALL IT PROPERLY

SOURCE: Flashing red light - no paper jam

I had this problem and couldn't figure out until I opened the front, pulled out the toner cartridge and found a paper jam.  Removed it and now I have the green light.

SOURCE: Canon MF3240 Paper Jam - No Real Jam

try this

1. Turn off the printer.
2. Remove any paper trays. Inspect them for wrinkled or damaged paper.
3. Also open the back cover of the printer if this model has one.
4. Open any other doors that give access to the printer's paper path and to the toner or ink cartridge.
5. If necessary, remove the toner or ink cartridge. Place it away from light/ sun light to avoid damaging it.
6. If you find a piece of jammed paper, remove it by holding it with both hands and pulling firmly. The goal is to keep the paper from tearing. If several pieces are jammed together, try pulling out the middle piece first to loosen the jam.
7. If the paper does tear, try rotating the roller gears manually to free the paper. Don't force anything, though. Do this step especially if the jam message comes up repeatedly without any obvious paper jam, there may be a small tear of paper inside.
8. Ones the printer is free of paper Replace the toner or ink cartridge and paper trays, close any doors you opened and turn the printer back on.
9. If the printer paper jam message still appears, then there is still some paper in the printer. Reinspect the paper path.
10. see alternative if the problem is still not solved.
    

SOURCE: my canon mx310 keeps showing a paper jam alarm and there is no paper jam. how do I fix it?

give this a try

1. Turn off the printer.
2. Remove any paper trays. Inspect them for wrinkled or damaged paper.
3. Also open the back cover of the printer if this model has one.
4. Open any other doors that give access to the printer's paper path and to the toner or ink cartridge.
5. If necessary, remove the toner or ink cartridge. Place it away from light/ sun light to avoid damaging it.
6. If you find a piece of jammed paper, remove it by holding it with both hands and pulling firmly. The goal is to keep the paper from tearing. If several pieces are jammed together, try pulling out the middle piece first to loosen the jam.
7. If the paper does tear, try rotating the roller gears manually to free the paper. Don't force anything, though. Do this step especially if the jam message comes up repeatedly without any obvious paper jam, there may be a small tear of paper inside.
8. Ones the printer is free of paper Replace the toner or ink cartridge and paper trays, close any doors you opened and turn the printer back on.
9. If the printer paper jam message still appears, then there is still some paper in the printer. Reinspect the paper path.
10. see alternative if the problem is still not solved.
    

SOURCE: paper jam in canon Imageclass D861 copy machine

Where inside in fixing unit, drum unit,...
It is problem if its fixing unit jam.Best take it to service