Chapter 2. Adjustments - Sharp UX-4000M - UX 4000 B/W Laser Printer Service Manual

CHAPTER 2. ADJUSTMENTS

[1] Adjustments
General
Since the following adjustments and settings are provided for this model,
make adjustments and/or setup as necessary.
1. Adjustments
Adjustments of output voltage (FACTORY ONLY)
1. Install the power supply unit in the machine.
2. Set the recording paper and document.
3. When the document is loaded, power is supplied to the output lines.
Confirm that outputs are within the limits below.
Output voltage settings
Power
Supply
PWB
1
CN101
12
2. High voltage power adjustments
The high voltage power adjustments are composed of the MC output
voltage adjustment and the DC bias output voltage adjustment. Either
adjustment is performed with the diag function. (MAIN CHG ADJUST
MODE)
1
MC output voltage adjustment
In the measurement circuit shown below, adjust VR1 to be –1050V ~
–1200V (aim at –1100V)
Measure with the high
voltage tester
(effective value meter).
• Capacitor: 1000pF/3KV (VCKYQY3FB102K)
• Diode: SHV-03 (VHDSHV03///-1)
Printer PWB
1
CNPW
12
Fig. 1
MC
DRUM
MC output
voltage check
+
–
2 – 1
UX-4000MU
FO-2950MU/C
Output Voltage limits
+5V 4.75V~5.25V
+24VH 23.04V~24.96V
+24V* 23.04V~24.96V
Connector
CNPW
No.
PIN No.
1 +5V
2 DG
3 DG
4 +24VH
5 MG
6 MG
7 +24VS
8 PWRLY–
9 HLON–
10 +24V
11 +24V
12 ZC
VR1 (MC output voltage adjustment volume)
Fig. 3
Fig.2