Problems Encountered Frequently In The Past; Problems Due To The User's Actions; Problems Due To Machine Malfunction; 1 ] Paper Jams - Brother MFC640CW Service Manual

9.2.5 Problems encountered frequently in the past

This section lists the four problems most frequently encountered during on-site service in the past.
- Paper jams
- Error message "MACHINE ERROR 4F"
- Ink-related problems
- Auto document feeder (ADF) failure

[ 1 ] Paper jams

A paper jam may occur not only due to machine malfunction but also to the user's actions.
IMPORTANT: In some cases, foreign material that has found its way into the machine without the
user realizing can be the cause a paper jam. Instruct the user to place nothing on top of the machine
that might fall into it.

Problems due to the user's actions

Check
Recording paper
For foreign
materials

Problems due to machine malfunction

Check
Star wheels on star
wheel support
Sensors and
actuators
Bank ASSY
CR encoder strip
Possible causes
Paper not suited to use with the
machine was used.
Fragments of paper that were left
behind when previous paper jams
occurred.
Foreign materials such as tacks
have found their way into the
machine.
Possible causes
Star wheels became dislocated
when paper jam occurred.
Any sensor(s) not working.
The bank ASSY has worn thin.
Bank ASSY
Paper tray
The CR encoder strip is stained.
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Problems that may result
Paper with labels attached, for
example, may leave labels
inside the machine.
Foreign materials can hinder the
paper feed.
Problems that may result
Dislocated star wheels can
hinder paper feed.
If a sensor does not turn on, the
related roller(s) will not rotate.
A worn section on the bank
ASSY can cause double-
feeding.
A stained CR encoder strip can
cause a carriage drive error
during printing that will stop the
printing operation.
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