Paper behind the trays

At least once per week we will get calls about a copier that has an error after a jam with a code C-0202, C-0204, C-0206 or C-0208. These codes will be displayed on a bright red screen that states that one of the paper trays can no longer be used. The message continues to ask if the user wishes to continue to press a "Continue" button on the screen then prompt the user to turn off then on the sub power switch which is on the control panel. If this is done as instructed the copier will work as normal except the affected paper tray will no longer be selectable. Usually the user will panic at seeing a scary red screen and call us or will fail to read the on screen instructions and turn the copier off and on at the main switch and will have the error again once the machine starts up.
The C-020x errors are common to all Konica Minolta Bizhub copiers and printers. The code refers to the paper tray lift motor malfunction and the last number refers to which particular tray is affected, 2 for tray 1, 4 for tray 2, 6 for tray 3 and 8 for tray 4. The error occurs when tray has been pushed into the machine and then engages the motor behind the tray that lifts the paper into the feed rollers above but the paper does not reach the upper limit sensor within a set period of time. If the machine tries to lift the paper in the tray but waits for a longer than reasonable time for either sensor that shows that the paper is at the correct height or the sensor that shows the tray is empty then the machine presumes something is wrong and stops.
While I have had a couple of lifting motor gearbox couplings fail in the last few years and once had an upper limit sensor fail these are fairly rare. Just about every time I see these errors it is because of a sheet of paper getting behind the tray and preventing the lift gearbox coupling with the lifting plate in the tray. The paper usually gets behind the tray if there is a miss-feed from the tray and the sheet ends up between the feed and separation rollers and the tray is then pulled out and the stuck sheet stays in the machine and falls behind the tray. When the tray is then pushed back in the sheet is pushed into the lift motor. To prevent this the on-screen instructions for clearing the jam and the instructions in the user manual both state that before pulling out the tray the lower right hand side door should be opened and any paper pulled out. But not many users read the instructions.
Removing paper from behind the tray is not as easy as it sounds even if know it is there. This is because of the group of switches behind each tray that detects the position of the guides in the tray to automatically detect the size of the loaded paper. To prevent accidental damage to these switches by people reaching into the machine the designers of the machines added brackets at the front to prevent the trays from being removed. The brackets are in different places on different models or even on different trays but are easy to spot if you know what you are looking for.
Once the paper is removed opening and closing the front door of the machine will clear the error code or if the tray has been locked out then switching the machine off and on at the main switch will allow the tray to be used again. After the tray can be used again the cause of the original jam should be investigated to prevent the chance of the same error happening again.
So the lesson is if you have a jam always check for paper in the right hand side of the machine before pulling the trays out.