Xerox Phaser 790, Service Manual

Page: 159 / 653

10/00
2-145
Phaser 790/DocuColor 2006
009-341
Status Indicator RAPs Initial Issue
009-341 ADC Sensor Background RAP
Control Logic has determined that the ADC sensor output while measuring non-imaged area is
higher than specification.
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.
Y
N
There is between -250 VDC and -350 VDC present.
Y
N
There is +24 VDC from pin 1 to pin 3 on J41.
Y
N
Go to Flag 4. Check for an open circuit. If the wire is OK, go to the 001-703
RAP
Access the Digital Output Test (GP 2). Enter code 0E. Press the Item/Enter button.
There is less than 1 VDC from pin 1 to pin 13 of J 42 on the HVPS.
Y
N
Go to Flag 2. Check for an open circuit. If the wire is OK, replace the MCU PWB
(PL 11.2).
Go to Flag 3. Check for an open circuit or a short circuit to ground. If the wires are
OK, replace the HVPS (PL 11.1). If the problem persists, replace the MCU PWB (PL
11.2).
Go to Flag 3. Check for an open circuit or a short circuit to ground. Go to Flag 5. Check for
an open circuit. If the wires are OK, check the BCR connector (PL 5.1) and the bias con-
nector on the Copy/Print Cartridge for damage or contamination. Clean, repair or replace
as required.
If the problem persists, replace the Copy/Print Cartridge (PL 5.1).
The ADC Sensor is dirty.
Y
N
Go to Flag 1. Check for an open circuit. If the wire is OK, replace the ADC Sensor (PL
5.1). If the problem persists, replace the MCU PWB (PL 11.2).
Go to the 009-340 RAP.