Fuser Door/s Regarding error message "Close Fuser Door" What is it? where is it? how do I close it? Colin

The fuser door is at the back of the machine. Open the door, pull down and close firmly shut. If the error persists it could be that the sensor has gone bad. The sensor is actually hard wired to the High Voltage Power Supply that sits right above the paper tray underneath the machine. It would need to be replaced if closing door doesn't fix the error, the part number is 105N02120,a link to picture of the part is 105N02120 Xerox 3300MFP HVPS Item Inc

there are 2 switches regarding this error message " front and rear cover open." so pls. check with the front door right side portion. you can see a small leaver there, pls. check that liver correctly go inside the cover after we close the front door.
other switch at the back door paper exit area. pls. check the door closed properly nor not ? that door control a switch liver attached with the fuser unit.
first switch in the HVPS board and second switch at SMPS.
kindly check it and revert back.

Its not talking about the bypass tray. Its saying the right side door isn't closed. There is a cover above the fuser that may not be closed. Open the right side door and see if you see any broken parts. If everything is closed correctly and not broken, the message will go away.

Are you sure it is not a NVRAM error you are recieving?

If yes, remove the IMAGING UNIT.
Close the door and Power On.
Msg gone? If yes, replace IMAGING UNIT.

If no, remove the FUSER unit.
Close the door and Power On,
Msg gone? If yes, replace FUSER.

If not, it is the ENGINE BOARD.

Error E000

Fuser did not heat up. check Fuser lamp, check thermistor, check thermostat, if this parts ok try to reset the trouble code. to reset fuser errors, first shut power off and turn on again. Then, go to service mode. Select "User mode" by pressing additional function ( * ) key then Press "ID" key ( # ) on user mode screen. Select menu 7 using cursor key. Press "OK" key. Select 4 item with cursor key. Press "OK" key. Printer reset. YES=( * ) to clear fuser error code E000


Error "check printer cover"

I think your problem is fairly simple if you have technical background. just check door compartment carefully there is a plastic part which presses the sensor switch or cover the optical sensor may be broken.

If not, then take a digital meter and ground the common probe and positive probe touch to the related sensor.there are two type sensor 1) switch type 2)optical, that they use.

If the switch type is used, when door is open voltage is 0,door close voltage is 5 volt although this may be reversed.

In the optical sensor case, one side is diode that is on 1.5 volt and other side photo transistor.
connect probe to trs side to collector or emitter depending on what biasing they use, then open door and see if the emitter goes high or low, repeat in door close position also if it goes properly high and low, if not then some other part is faulty.

If you are not sure how to do this then call in a technician

There is a switch that should "close" when the door closes.
But, that switch either is damaged, or it is not sending the "now closed" signal to the printer.

Check that there is no obstruction blocking that switch, nor any dust plugging it up.

The error has to be manually reset. Here is what I found from the official procedure. Hope it works. How to clear a fuser error code (C0500, C0501, C0510, C0511, C0520, C0521). Solution To clear the fuser error code, perform the following after correcting the cause:
1. With power ON, open the front door and locate the small, rectangular hole below the imaging unit removal tool.
Note: It is not in the same location as the models 7915/7920.
2. Insert a suitable object into the hole to actuate the reset switch .3. The code should clear and a message to close the front door should appear.

How to clear a fuser error code (C0500, C0501, C0510, C0511, C0520, C0521).Solution To clear the fuser error code, perform the following after correcting the cause:
1. With power ON, open the front door and locate the small, rectangular hole below the imaging unit removal tool.
2. Insert a suitable object into the hole to actuate the reset switch .3. The code should clear and a message to close the front door should appear.

the error codes means Low fuser temperature during warm-up
To clear the fuser error code, perform the following after correcting the cause:
1. With power ON, open the front door and locate the small, rectangular hole below the imaging unit removal tool.

2. Insert a suitable object into the hole to actuate the reset switch .
3. The code should clear and a message to close the front door should appear.

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