My Canon NP6545 gives me the error "close the upper right door". I have closed all doors several times but the error does not reset. Thanks for your answer in advance. AC.

ther is a pin on the door that stick into agrove in the copier frame were there is a savety swicth if the door open it cuts the harmfull vots this pin brakes off and the switch dont get pressed

I would try closing the door, then power off and unplug the printer for at least a minute. This may clear out the error.
If still no go, open the door and make sure there is nothing blocking the door from closing completely and also locate the door sensor and inspect for damage to the sensor as well as the part of the door that disables the senor / interacts with the sensor when the door is closed.

Check that the front door magnets are still attached to the door. They can come out of their holders and this will cause the front door not to close properly. They are easy to snap back in. Squeeze the sides,then put it back in it's holder. There are 2 magnets. One on the upper corner and one on the lower corner. You must reset the power to clear this error. Also check that the door closes properly by holding the top right side shut. I have had to bend the door switch bracket out to make proper contact. Check that the cover of the duplex tray is all the way on,too. If it is loose on the lower right corner it can interfere with the front door. After checking these items,reset the power to clear code.

Check the rollers and open and close the door. If everything looks okay, the sensor is not sensing there is paper causing the error.

Press the off button and hold for 5 seconds if this does not work un plug and it should reset.

Hello sir; Did you recently replace new toner, if you did, please go back to check out does the door close right, otherwise you have to check the corona wire is broken?

Try to open and closed the front door several times,If the left cover and the front door are closed properly and still showing "close front door" most
probably the internal contact of door switch are not good , door switch replacement is needed

when you open the front door you,ll find under the disply a smal hole put eny nail in it a doller sign will apeer in the upper left corner of the disply pres
star , 4,star you will see another disply press the right arrow till you find error word press on it and then press star (astresk. the disply will turn off and on again theis error might be from the heater lamp if
it comes again change the hamps

my dear Your printer's lower door must be completely closed before the upper door is rotated downwards and closed.  If you close the two doors at the same time, a mechanism inside the printer may become dislodged and return an error message. heres the step i teach to you, it is not a fake this is my thrisck , and many people are success of my guide, hope it was also helpfull to you. step 1 Power off the printer. 2 Remove the fuser assembly and carefully set it aside.
3 Locate the link on the top right side of the printer where the fuser used to be. 4 Using the eraser-end of a pencil or similar tool, reposition the link into the metal track. 5 Once the link is positioned, rotate the upper door while holding the link in position to ensure it travels properly along the metal track. 6 Replace the fuser and secure the thumbscrews. 7 Power the printer back on to see if the error has cleared. If the error persists, contact Lexmark technical support for assistance. or just tell me for confirmation. thanks god bless

I had the same problem happen tonight. I have an XL44 self-cleaning gas range. We unplugged it for several minutes and pressed 'cancel' a bunch of times--neither worked. We finally lucked out--opened the oven door and pressed a black button on the upper left side of the front of the oven. It turned out the flashing words and unlocked our door. Weird. There was nothing in the manual about this...