Xerox Phaser 790 User Manual

10/00
3-7
Phaser 790/DocuColor 2006
IQ4, IQ5
Image Quality
Initial Issue
IQ4 High Density RAP
Initial Actions
• Check the end-of-life counters for the Dry Ink Cartridges and the Copy/Print Cartridge
(GP 3). Replace if required.
• Perform VisualCal. If this does not resolve the problem, continue with this RAP.
Procedure
The problem involves a single color only.
YN
Remove the Rear Cover. Observe the Dispense Clutch as a test print is being made.
The Dispense Clutch remains energized constantly.
YN
Go to the 009-340 RAP to check the functioning of the ADC Sensor.
Go to the 009-342 RAP to troubleshoot the Dispense Clutch.
Check the following:
• Check the Developer Roll spacing (ADJ 9.1) for the affected developer.
• Clean the HV contact for the developer in question.
• Replace the Dry Ink Cartridge (PL 6.2) if not done previously
• Replace the Developer Housing (PL 6.2).
IQ5 Solid Black (or other Color) Sheet RAP
Procedure
WARNING
HIGH VOLTAGE!
Exercise care when making the voltage check in the following step.
CAUTION
Do not allow [DO-0E] to run for more than 10 seconds. As soon as the measurement is com-
plete, use the DO Stop Test to cancel switch off the bias.
Access the Digital Output Test (GP 2). Enter code 0E. Press the Item/Enter button. There is
between -400 and -600 VDC from the A terminal of the HVPS to frame ground.
YN
Go to the 009-341 RAP to troubleshoot the BCR bias circuitry.
Remove the Copy/Print Cartridge. Use a folded sheet of paper to block the light from the ROS.
Reinstall the Copy/Print Cartridge. Make a test print. The defect remains.
YN
Replace the ROS (PL 5.1). If the problem persists, replace the MCU PWB (PL 11.2).
Replace the Copy/Print Cartridge (PL 5.1). If the problem remains, replace the MCU PWB (PL
11.2).

Xerox Phaser 790 Specifications

General

Brand	Xerox
Model	Phaser 790
Category	Copier
Language	English