I need help with my G7000 Cannon printer and do not understand the on-line manual. How do I change from the rear paper feed to the front paper cassette?

I suspect the printer is defaulting to manual feed because it thinks there is a page in the manual paper feed. Make sure no bits of paper debris are jamming the sensor.

The error code 5700 is the sensor error.Replace the sheet
feed unit and then adjust the timing of the paper feed gears.

Most of our printers pull the paper down on one side slightly faster than the other. The printer hardware should even this out when printing. You should also ensure the paper meets the automatic feeder requirements of the printer.
If printing is skewed, feeding multiple pages or jamming, please follow these instructions (use a regular letter size paper to test after doing the steps given below):
Please check to ensure there is nothing obstructing the paper feed mechanism down inside the printer where it is not easily seen. If there is nothing obvious, unplug the printer and remove the paper. Open the front cover and look above the steel rod. You should see a conveyor belt with rubber teeth on it, like a fan belt. Take the bottom part of that belt and move it gently to the left. The cartridges should come out with it. Make sure the cartridges can move fully from one side of the printer to the other. Check also the output rollers on the bottom of the printer for any blockage. If it is jamming under the carrier assembly, you may be able to fix it using the manual feed slot. Turn the printer off. Next take a #10 envelope and feed it through the left side of the paper feed slot (The manual paper feed slot is preferred, but the automatic feed will do if there is no manual paper feed for this printer) until it comes completely through the printer to the back of the exit rollers. Move it up and down and slowly move it over to the right side. If something is stuck under the black guide plate this may work it loose or you may have to feed the envelope through the front rollers and push your way backward (please be careful here).
Next, take a damp warm cloth and clean the rubber rollers in the automatic sheet feeder. Dust may be coating the rollers there and as they become less tacky, they cannot feed paper correctly.
Finally, turn the printer upside down and carefully shake it for 10 to 20 seconds to see if something falls out of the paper feed path. Then plug the printer back up, take your paper out and replace it with a fresh, small stack (about 5 pages) of paper. Quickly bend the stack in an 'S' shape a few times to separate pages. Make sure it is lined up on the right side of the paper feed and the paper guide on the left is snug on the left side of the paper. Then try to form feed again. If that works, then try to print again.
If it still fails to feed the paper correctly, please reply with the following information:
What type and brand of paper were you using? Have you ever used this type or brand of paper before and if so what were the results?

Had this problem yesterday, then after downloading the manual you need to
switch feed (left hand side). There are two feeders in the rear and pull out tray
at front, very bottom.

Hope this helps !

Normal 0 I suggest you get a sheet of Card Stock (Heavy paper) and place it in the feed way. Then press the print button applying a slight amount of pressure on the Card Stock so it will feed through the printer. The reason for this is in some cases I have been able to clear the paper track of debris that was deposited there over time.
Worth a try, as I have fixed a number of printers this way, saving costly repairs.
Hope this helps. Bud

Clean the feed rollers.

there should have a wheel (knob)right on the paper exit area, just close it , paper will be come out to front

Yes, use the "feed switch" button on the front of the printer. There are small lights that indicate the paper tray to be used.

I assume you are trying to use the front path? If so simply press PARK and then press the PATH button to change it back to FRONT FEED.

When it runs out of paper it changes paper paths automatically looking for more loaded paper (AUTO-PATH feature).

Anyway, that's what happened to us.

Dont buy a cannon ever again