SHARP SP1972 Technical Report

Date: Nov. 30, 1995

COPIER : SF-2116

1. MEASURE TO PREVENT U2 TROUBLE.

2. MEASURE TO PREVENT THE CLUTCH IN THE MANUAL MULTI PAPER FEEDING UNIT
FROM SLIPPING.

3. MEASURE TO PREVENT THE CORNERS OF THE LEADING EDGE OF THE COPY PAPER
FROM FOLDING.

4. MEASURE TO PREVENT PRINTING MIS-COPIES (WASHED-OUT COPIES) DUE TO
MOISTUR E ABS O RBANCE OF TH E CO PY PAPER.

No. : SP-1972

1. Measure to prevent U2 trouble.

1.Model name: SF-2116/ 2118/1016/1018

2.General: The IC (ROM) in the main PWB was changed to version 2.5 from the start of 1995 July

production, but there was a possibility of U2 trouble occurring due to the extremely rare
conditions described below. To alleviate this problem, a change was carried out on the
software, and version 2.5 was changed to version 2.6.

There was a possibility of U2 trouble occurring when the power supply of the machine
was turned off immediately after delivery of the last copy during multi copy operations,
and then turned back on again. This problem occurred as a result of a particular timing
between the delivery of the last copy and the turning off of the power supply of the
machine, and as a result, there is basically no problem during normal operations.
The ROM label shown below has been used with a portion of the August production lot
of model SF-2118, but the ROM version is the same, version 2.6.

SWALLOW

Main V2.5

Green

3.Action: From the start of 1995 August production.

2. Measure to prevent the clutch in the manual multi paper feeding unit from slipping.

1.Model name: SF-MF15

2.General: Slipping sometimes occurred in the one-way clutch in the manual multi paper feeding

unit. This problem was considered to be a result of the diameter of the manual paper
feeding bearing being a little too small. To alleviate this problem, a change was carried
out on the tolerance of the diameter of the bearing.

Old New
φ5 → φ5

-002

-007

0

-003

SHARP CORPORATION Reprography Division

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Green

C

3.Action: From the start of 1995 October production.

3. Measure to prevent the corners of the leading edge of the copy paper from folding.

1.Model name: SD-21 16/21 18/ 1016/1018

2.General: There is a possibility of the corners of the leading edge of the copy paper folding when

thin copy paper for use in the Japanese domestic market is used in machines with a
sorter installed. To alleviate this problem, the measure described below has been
carried out.

3.Description: A change has been carried out in the material used in the discharge brush of the fusing
unit, and the pressure of the brush has been lessened (softened).

4.Action: Running change from 1995 mid-September production.

4. Measure to prevent printing mis-copies(washed-out copies)due to moisture
absorbance of the copy paper.

1.Model name: SF-2116/ 2118/1016/1018

2.General: The resistance of the rubber of the PS lower roller is low and the electrical charge

during printing operations is transferred through the PS roller from the copy paper to
GND. When copy paper that has absorbed moisture is used, printing mis-copies
occurs (washed out copies). To alleviate this problem, the measure described below
has been carried out.

3.Description: The rubber of the PS roller has been changed to one with a higher resistance.

In accordance with the change described above, the parts code for the PS lower roller
has also been changed, and the old and new parts can be distinguished apart by the
method described below.
Method of distinguishing between the old and new parts:
Temporary: Black marking on the end of the bearings.
Permanent: A center hole has been added to the end of the bearings

(toward the front of the machine).

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Center hole