Xerox DocuColor 12/DCCS50, Service Manual

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DocuColor 12/DCCS50
IQ 47 ATC Sensor RAP
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IQ 47 ATC Sensor RAP
The purpose of the Automatic Toner Concentration Sensor, ATC, is to detect toner concentra-
tions within the color developer housings (Y, M, and C). The DC12 process controls use the
input from the ATC Sensor to maintain TC in the 5-10% range (as described below) minimizing
TC related defects such as BCO and Starvation. BCO or Bead Carry Out commonly occurs
when the TC drops below 5%. BCO appears as mottle or white spots in high-density areas.
Starvation can occur when the TC exceeds 10%. Starvation appears as a deletion at the
boundary between a high and low-density area.
In the DC12 (DCCS50), 65% Y, M, C ADC process control patches are periodically read by the
ADC Sensor and compared to ADC Targets. If the readings are not within a specified range of
the targets, the machine will tone up or down as required. The machine is constantly adjusting
the ADC Targets based on input from the Humidity Sensor and ATC Sensor. The process con-
trols attempt to maintain densities across different environments while maintaining TC in the 5-
10% range.
For Black, the machine monitors a 60% and 100% ADC patch. Since the ATC Sensor cannot
measure Black TC, the 100% Black ADC patch was implemented in software 6.002 or Tag#16.
The ATC Sensor consists of; ATC Sensor Assembly, wire harness (J\P 423 on the IOT Drive
PWB), Plate assembly, and an assisting IOT Drive PWB. Troubleshooting the functionality of
the ATC Sensor is mainly executed through NVM read and write. dC330 component control
has been implemented.
Appendix 1 is the set-up procedure to turn ATC Sensor on for machines with software v7.5.3.
SOFTWARE (NVM) REPAIRS:
1. The machine must have software version V6.00.2 or higher installed.
2. Make sure NVM 775-731=1on (ATC function 0=OFF / 1=ON)
3. Check the value of NVM 775-815 (TC set average). Software v6.2.0 has default 250 with-
out ATC Sensor set-up. Software v6.00.x has default 0 without ATC Sensor set-up. (See
Appendix 3c). The value can also be affected by the space between the ATC Sensor and
the Developer Housing Mag- Roll. See Appendix 1 for re-setup instructions. After a suc-
cessful set-up, NVM 775-815 should be between 150 – 230.
4. Using Table 1 , confirm that the following NVM values are 1. If any of the values are 0,
repeat steps b) through g) of Appendix 1. After steps b) through g) are completed, refer
back to Table 1 and confirm that the values are all 1. If any values are 0, refer to the recov-
ery procedure listed for the corrective action.
Recovery procedure at NVM Failure
Action 1: Replace the ATC Sensor and verify the connection.
Action 2: Verify shutter operation. dC330 component controls 009-039 shutter operation.
(See step 8).
Action 3: Ensure the Sensor/reference plane is free from contamination.
Action 4: Verify correct installation of the ATC Sensor Assembly.
5. Check the following NVM. 775-761 (Measurement TC Sensor Dark Current) value should
be less than “200”. Check 775-762 (Measurement of TC Reference Plane) value range
“200” ~ “600”. If NVM are not within given range, perform step 8 (dC330 component con-
trol). If NVM are not within range after dC330 (step 8), ensure the ATC Sensor and shut-
ter is free from contamination. If problem continues perform steps b) through g) of
Appendix 1. If problem continues refer to the “Hardware Repairs.”
6. ADC Targets. Check the NVM and change to given value if necessary. The ADC Targets
must be set to nominal values. 773-266=230; 773-267=230; 773-268=250; 773-269=160.
If any of the NVM values are not set to nominal, correct values and perform steps b)
through g) of Appendix 1.
7. When ATC Sensor is installed, specified developer is noted by NVM. Machines from man-
ufacturing should have all new color developers. If ATC Sensor was installed in field, then
the developer that is replaced must be specified by NVM. Check the NVM and ensure it
corresponds with specified developer. (775-737 see Appendix 1e).
8. dC330 (Component Control) after the ATC Sensor is implemented.
The following dC330 routines have been added according to the ATC Sensor implemen-
tation:
Table 1
NVM Content
775-741 Dark current failure
775-742 Reference plane output failure
775-743 Y_TC measured value failure
775-744 M_TC measured value failure
775-745 C_TC measured value failure
775-746 Shutter open/close failure
775-747 Y_TC measured value failure at setup
775-748 M_TC measured value failure at setup
775-749 C_TC measured value failure at setup
775-750 Setup failure, any of the above failures
Table 2
NVM Value
1 = OK
0 = NG
Content
NG action
(perform
action
below)
775-741 Dark current failure 1
775-742 Reference plane output failure 3, 2, 1
775-743 Y_TC measured value failure 4, 2, 1
775-744 M_TC measured value failure 4, 2, 1
775-745 C_TC measured value failure 4, 2, 1
775-746 Shutter open/close failure 2
775-747 Y_TC measured value failure at setup 4, 2, 1
775-748 M_TC measured value failure at setup 4, 2, 1
775-749 C_TC measured value failure at setup 4, 2, 1
775-750 Setup failure (any of the above failures 3, 2, 1
Table 1
NVM Content