Lexmark C 746 Service Manual

Diagnostic aids3-49
 5026
Go Back Previous
Next
240 paper jam
If paper is jammed in Tray 1, 241.xx Paper jam appears. If paper is jammed in any of the optional trays, 24x.xx 
Paper jam appears. 
•If the jammed paper is located in tray 1, follow these steps to remove the paper from tray 1.
1.Open tray 1, and pull the jammed pages straight up and out.
2.If the jam is located in front of the tray, pull the jammed pages up and out.
3.After removing the tray, the front door may need to be opened to access the...

3-50Service Manual 5026 
Go Back Previous
Next
250 paper jam
If paper is jammed in the multipurpose tray, 250.xx Paper jam appears.
1.Press the paper release lever, and then remove the jammed pages from the multipurpose tray.
2.Load new paper into the multipurpose tray.
3.Press   or touch  .
1
2 

Diagnostic aids3-51
 5026
Go Back Previous
Next
Theory of operation
Paper path 

3-52Service Manual 5026 
Go Back Previous
Next
Main Components
System board
The system board provides the intelligence of the printer. Command and control signals originate in the system 
card that make print media travel possible. The system card controls the timing of the print media during the 
printing so the media arrives at certain positions in the print process at certain times.
Paper tray
Houses the print media.
Paper pick mechanism
Picks the print media from the paper tray. The paper pick...

Diagnostic aids3-53
 5026
Go Back Previous
Next
Print media transport
The print media is picked from the input source and fed to the bump aligner roll. The media movement is 
detected by a sensor located in the paper pick mechanism. It does not matter where the media comes from 
(Tray 1, Tray 2, or, the MPF); it will enter the electrophotographic process at the bump aligner drive. The bump 
aligner motor drives the bump aligner roll which feeds the paper to the transfer belt. 
500-sheet assembly
pick...

3-54Service Manual 5026 
Go Back Previous
Next
Once the paper is fed onto the transfer belt, the photoconductor drums in conjunction with the transfer belt pull 
the print media through the paper path.
Photoconductor
drums
Transfer belt 

Diagnostic aids3-55
 5026
Go Back Previous
Next
Once the print media exits the transfer belt, it enters the fuser where heat and pressure are applied to bond the 
toner permanently to the media. The fuser rollers continue to turn and pull the print media through the paper 
path until it reaches the exit drive roll. The exit drive roll pulls the print media from the fuser rollers and delivers it 
to the fuser output drive roll. Once the print media reaches the fuser output drive roll, the roller pushes...

3-56Service Manual 5026 
Go Back Previous
Next
If the page is to be duplexed, the fuser output drive roll continues to pull the media until it clears the paper exit 
flag and then reverses the rotation of the roller in order to pull the media back into the printer duplex assembly. 
The media is then routed down through the duplex path until it reaches the bump aligner roll. Once in this 
position, it enters the EP path for the second time.
The paper exit flag serves two purposes. When it triggers the...

Diagnostic aids3-57
 5026
Go Back Previous
Next
Mechanical drive
In order for the print media to move through the paper path, there are several drive motors that supply the 
mechanical power to the rollers discussed previously. The drives for these components are illustrated and 
discussed in the following paragraphs.
Paper pick mechanism drive
When printing from Tray 1 or Tray 2, the paper pick motor drives the paper pick gears which causes the pick 
roller to turn. During an MPF print, the paper pick...

3-58Service Manual 5026 
Go Back Previous
Next
Bump aligner drive
The power to turn the bump aligner roll is supplied from the bump aligner motor. The motor drives a set of bump 
aligner gears which causes the bump aligner roll to turn.
Note:  If this motor is stalling or causing waste toner box full messages, the vertical auger mechanism might be 
causing the problem.
Bump aligner roll
Bump aligner gears
Bump aligner gears
Bump aligner motor