Copy Density Adjustment Procedure; High Voltage Adjustment; Main Charger (Grid Bias) - Sharp AL-2020 Service Manual

E. Copy density adjustment procedure
Use SIM 46-1 to set the copy density for each copy mode.
For selection of modes, use the [Exposure mode selector] key (or
[ ] [ ] key for the AL-2050/2060).
(1) Test chart (UKOG-0162FCZZ) setting
1) Place the test chart so that its edge is aligned with the A4 (Let-
ter) reference line on the document table. Then place a A4
(14" x 8 1/2") white paper on the test chart and close the docu-
ment cover.
White paper
Test chart
(2) Perform the adjustment in each mode.
1) Execute SIM 46-01 (300dpi). To adjust in 600dpi, execute SIM
46-02.
2) AL-2020/2035/2040
Select the mode to be adjusted with the exposure mode select
key. Set the exposure level to 3 for all adjustment. (Except for
the auto mode.)
(1) (2)
(1) Exposure mode select key/display lamp
(2) [Exposure mode selector] key/
display lamp
Adjustment Exposure mode
mode display lamp
Auto mode Auto lamp ON
Manual mode Manual lamp ON
Photo mode Photo lamp ON
Manual T/S Manual lamp/Photo lamp ON "3" is slightly copied.
mode
Auto T/S Auto lamp/Photo lamp ON
mode
2) AL-2050/2060
Select the mode to be adjusted with the [AUTO] key. Set the
exposure level to 3 (center) for all adjustment. (Except for the
auto mode.)
TEXT
| | | | |
1 1 2
2 2
2 1 1
Sharp gray chart
adjustment level
"3" is slightly copied.
"3" is slightly copied.
"3" is slightly copied.
"3" is slightly copied.
(1) Exposure mode, level display
(2) [AUTO] key
AL-2020/2035/2040/2050/2060 ADJUSTMENTS 9 - 5
Adjustment Display
mode item
Auto mode AE COPY mode lamp "3" is slightly copied.
Text mode TEXT PRINT mode lamp "3" is slightly copied.
Photo mode PHOTO SCAN mode lamp "3" is slightly copied.
Text T/S mode TSTXT PRINT mode lamp
SCAN mode lamp
Auto T/S mode TSAE COPY mode lamp
SCAN mode lamp
3) Make a copy.
Check the adjustment level (shown in the above table) of the
exposure test chart (Sharp Gray Scale).
Sharp Gray Scale adjustment level
Non toner
1 2 3 4
save
mode
Slightly copied.
Not copied.
Toner
1 2 3 4
save
mode
Slightly copied.
Not copied.
(When too bright): Decrease the value displayed on the copy
quantity display.
(When too dark): Increase the value displayed on the copy quan-
tity display.
∗
The value can be set in the range of 1 - 99.

3. High voltage adjustment

A. Main charger (Grid bias)
Note:
• Use a digital multi meter with internal resistance of 10MΩ or
more measurement.
• After adjusting the grid LOW output, adjust the HIGH output. Do
not reverse the sequence.
Procedures
1) Set the digital multi meter range to DC700V.
2) Set the positive side of the test rod to the connector CN11-3
(GRID) of high voltage section of the power PWB and set the
negative side to the frame ground (power frame).
3) Execute SIM 8-2. (The main charger output is supplied for 30
sec in the grid voltage HIGH output mode.)
4) Adjust the control volume (VRG1) so that the output voltage is
580 ± 12V.
Sharp gray chart
LED
adjustment level
"3" is slightly copied.
"3" is slightly copied.
5 6 7 8 9 10 W
5 6 7 8 9 10 W
VRG1