Paper Jams In The Paper Feed Side; Paper Jams In The Paper Eject Side - Duplo Duprinter DP-43E Service Manual

(12) Paper Jams in the Paper Feed Side

Causes
Printing paper not suit-
able
Dirt*foreign matter in
transfer path
Incorrect paper feed path
pressure
Worn paper feed roller
Paper separator unit gap
Paper separator unit
Separation pressure
Paper tray upper position
limit
Paper feed amount
Paper feed clutch
Guide roller pressure &
timing
Timing roller
Incorrect signal lever
operation
Symptoms
• If paper is too thick, it won't be likely fed. If too thin, dou-
ble sheets may be fed.
• Paper not clearly cut: 2 sheets still adhere to each
other.
• Much paper scraps may deteriorate the paper feed
roller and separator performance.
• Paper gets stuck in transfer path, causing creasing and
tearing.
• If pressure on paper is insufficient, paper will not be fed.
• If pressure on paper is excessive, double sheets will be
fed.
• Paper may not be fed.
• If gap is too large, separator unit will rattle in direction of
paper transfer path, causing double sheets to be fed.
• If gap is too small, paper separator unit cannot follow
angle change due to paper feed shaft up-down move-
ment, which may cause double-sheet or slanted feed,
and creasing.
• Wear, or adhesion of paper scraps causes deterioration
in separating performance, resulting in double-sheet
feed.
• If pressure is very low, no paper will be fed.
• Paper slant is large, causing creases.
• During printing, paper feed errors often occur immedi-
ately before or after paper tray rises.
• If amount is too short, paper slant cannot be corrected,
printing position may not be uniform, or paper may not
be fed.
• If amount is too long, loop becomes too large, causing
paper to buckle up between paper feed roller and timing
roller, resulting in feed error.
• Clutch slippage will reduce paper feed amount.
• If clutch does not disengage properly, the paper feed
segment gear will not return correctly, leading to
reduced feed amount.
(See "Paper feed amount" above.)
• If Guide roller pressure is insufficient, paper will not be
gripped properly, and timing roller will not assure con-
stant feed amount. As a result, printing position will not
be uniform. In the worst case, no paper will reach drum.
• If there is a gap between Guide roller and the timing
roller, paper slant cannot be corrected.
• If the timing roller clutch slips, feed amount will not be
constant. As a result, printing position will not be uni-
form. In the worst case, no paper will reach drum.
• If the timing roller clutch does not disengage properly,
the paper feed segment gear will not return correctly,
leading to reduced and unstable feed amount. As a
result, printing position will not be uniform. In the worst
case, no paper will reach drum.
• Paper may be damaged in the part of leading edge that
touches the signal lever. In the worst case, paper may
stick to the signal lever.
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chap.6
zTroubleshooting Guide
Countermeasure
Explain causes to user. Have user
change to the paper conforming to
specifications.
Remove any dirt or foreign matter.
Explain to users how to select cor-
rect pressure for paper.
Replace paper feed roller.
Perform paper separator unit gap
adjustment.
Clean separating surfaces. If any
trouble exists, replace. Perform sep-
arator unit gap adjustment on new
unit.
Perform separation pressure adjust-
ment.
Perform paper feed amount adjust-
ment.
Perform paper feed amount adjust-
ment.
Perform paper feed clutch gap
adjustment. If necessary, replace
clutch.
Perform escape amount adjustment
and escape timing adjustment.
Clean timing roller clutch . Replace
if necessary.
Clean bearing unit. Check that sig-
nal lever moves smoothly.