Canon printer PIXMA MX850 User Manual

127 Routine Maintenance
3With a soft, clean, lint-free and dry cloth, wipe 
off any paper dust from the inside of the 
Document Feeder Cover (A).
4After wiping, close the Document Feeder 
Cover by pushing it until it clicks into place.
5Close the Document Tray.
„Cleaning the Paper Feed Roller (Roller Cleaning)
Clean the paper feed roller if paper is not fed properly. Cleaning the paper feed roller will wear 
the roller, so perform this only when necessary.
1Make sure that the machine is turned on, and...

128Routine Maintenance
7Repeat (4) and (5) in step 3 three times.
The paper cleans the paper feed roller as it feeds through the machine.
If the problem is not resolved, turn off the machine, disconnect the power cord, and then wipe 
the paper feed roller (A) located on the right side inside the Rear Tray with a moistened cotton 
swab or the like. Rotate the roller (A) manually as you clean it. Do not touch the roller with your 
fingers; rotate it with the cotton swab.
If the problem is still not...

129
Routine Maintenance
4Load only this sheet of paper in the Rear 
Tray with the open side to the front.
5Perform bottom plate cleaning.
(1) Press the  Menu button.
(2) Use the  [ or  ] button to select  Maintenance/settings , then press the OK button.
The  Maintenance/settings  screen is displayed.
(3) Use the  [ or  ] button to select  Maintenance, then press the  OK button.
The  Maintenance  screen is displayed.
(4) Use the  { or  }
 button to select  Bottom plate cleaning , then press the OK...

130Routine Maintenance
„Cleaning the Protrusions Inside the Machine
If protrusions inside the machine are stained, wipe off any ink from the protrusions using a cotton 
swab or the like.
CautionzBe sure to turn off the power and disconnect the power cord before cleaning the machine.
zThe power cannot be turned off while the machine is sending or receiving a fax, or when there 
are unsent faxes stored in the machine’s memory.
zThe machine cannot receive faxes when the power is turned off.
zIf you...

131
Troubleshooting
Troubleshooting
This section describes troubleshooting tips  for problems you may encounter when using the 
machine.
z “An Error Message Is Displayed on the LCD” on page 133
z “LCD Cannot Be Seen At All” on page 138
z “An Unintended Language Is Displayed on the LCD” on page 138
z “Cannot Install the MP Drivers” on page 139
z “Cannot Connect to Computer Properly” on page 140
z “Print Results Not Satisfactory” on page 141
z “The Print Result Not Satisfactory When Copying” on page 144
z...

132Troubleshooting
If an Error Occurs When the Machine Is Connected to a Computer
When an error occurs in printing such as the machine is out of paper or paper is jammed, a 
troubleshooting message is displayed automatically. Take the appropriate action described in the 
message.
The message may vary depending on the version of your operating system. 

133
Troubleshooting
An Error Message Is Displayed on the LCD
If an error message is displayed on the LCD, take the corresponding action described below.
MessageAction
“The ink may have run out. Replacing 
the ink tank is recommended.”
U041 If the lamp on the ink tank is flashing, ink may have run out.
Replacing the ink tank is recommended.
If printing is in progress and you want to continue printing, press the 
OK button 
with the ink tank installed. Then printing can continue. Replacing the ink tank is...

134Troubleshooting
“The following ink tank cannot be 
recognized.”
U043
U140
U150 z
The ink tank is not installed.
Install the ink tank.
See “Replacing an Ink Tank” on page 107.
z The ink tank is not compatible with this machine. (The lamp on the ink tank is 
off.)
Install an appropriate ink tank.
See “Replacing an Ink Tank” on page 107.
z An Ink tank error has occurred. (The lamp on the ink tank is off.)
Replace the ink tank.
See “Replacing an Ink Tank” on page 107.
“The ink has run out. Replace the...

135
Troubleshooting
“Auto head align has failed. Press OK 
and repeat operation. ” Possible causes are as follows:
z
Print Head nozzles are clogged. 
Press the  OK button to dismiss the error message, and print the nozzle 
check pattern to check the status of the Print Head. See “Printing the Nozzle 
Check Pattern” on page 115 and “Printing Does Not Start/Printing Is Blurred/
Colors Are Wrong/Straight Lines Are Misaligned” on page 142.
z Paper of size other than A4 or Letter is loaded in the Rear Tray....

136Troubleshooting
“Document size is too long. Redo 
operation after checking document on 
ADF and pressing OK.” The document is too long or is jammed in the ADF. Remove the document page 
jammed in the ADF, then press the 
OK button. When the error is cleared, make 
sure that the document you are loading meets the machine’s requirements 
before redoing the operation. See “Original Document Requirements” on 
page 16 and “Document Jams in the ADF” on page 152.
“Document size not suitable for two-
sided...