Ever wonder what happens during dC-951 Initialization? And have you ever wondered what all those numbers really mean? Hopefully this information will help you in troubleshooting copy quality issues and make your Docutech perform at its peak performance. Actually, I was one of those techs that wondered what the heck was happening during dC-951 Initialization and also (secretly) praying that it would run to its completion with no problems or shutdowns. I can’t remember the number of times I actually had my fingers crossed while this program did its magic in the Docutech, and I think it would be safe to say it happened often. Actually, dC-951 contains a number of programs that will automatically adjust all the parameters that will affect copy quality and performance.

As you gain experience working on this family of printers, confidence on your part becomes more noticeable and you will even feel better about yourself. I know because it happened to me the same way after several months on the job.

Parameter                                    Value                   Range

ESV Monitor                                                             22 - 35
DSS calibration                                                         218 - 246
ACV Setpoint                                                            210 – 245
ACV Slope                                                                73 +-3
ESV Offset ID2 - 4                                                    0+5
ESV Offset ID6 - 4                                                    0+5
Hi Charge Dark Decay                                               26 + 20
LO Charge Dark Decay                                              20 +16
Dark Decay Intercept                                                 0 – 35

Before you enter Diagnostics to run dC-951, there are several things you should do to insure that the program runs to its completion. Open both doors and make sure that all covers and panels are installed properly. Keep in mind that a light leak will affect the process, especially in the patch area, and can cause the machine to set up incorrectly. Never run dC-951 with the front doors open or with any rear panels removed.

Check tray 3 to make sure that four reams of white 20 pound 8 ½ x 14-inch paper is loaded and the paper supply is properly programmed. I prefer 14-inch paper because it allows you to see if the dicorotrons are properly balanced (top to bottom). If this were a new installation or a new customer, it would be in your best interests to check the Dicorotron charge height (ADJ 9.7), balance (ADJ 9.8) and ESV height (ADJ 9.5) before running dC-951. The set-up procedure will be more precise if all the Xerographic components are clean and adjusted properly.

It’s interesting to note that when you power up the printer, it will automatically run the dC-951 Xerographic set-up procedure prior to the first print being delivered to the finisher. Occasionally, you may get the message on the screen “Please wait, Adjusting Print Quality” and that’s because it is trying to run dC-951 in the background. If this happens once in a while don’t worry about it; however if you are plagued with this message every single day, then you will have to troubleshoot the problem to resolve the issue. Make sure the correct Dicorotrons are installed and they are clean. Check the adjustments for all the components in the Xerographic process.

dC-951 Automatic Xerographic Setup

ESV Monitor: When dC-951 is powered up, any charge on the PR belt is cleaned off. The ESV (Electrostatic Voltmeter) will read the charge on the belt and report to the Control Logic with a zero (0) to ten (10) volt signal. In all reality there is no charge on the belt (at this time) and the signal should be zero (0) volts. The ESV Monitor, however, has a one-volt offset built in and this offset signal is displayed in bits. So, one volt would be displayed as 25.5 bits well within our parameter.

DSS Calibration: Before a latent image is developed, the DSS (Density Sample Sensor assembly) will measure the reflectance of a clean patch on the belt and will report to the Control Logic with a zero (0) to ten (10) volt signal. When the belt is clean, it will produce the maximum voltage— 10 volts. The DSS Monitor signal has a built-in offset of one (1) volt and the screen will display about 236 bits.

ACV Setpoint: This represents the AC voltage that is applied to the Dicorotrons. The process control will try to adjust the output of the High Voltage Output module until the ACV ratio is within specification. When the ratio gets to where it’s supposed to be, the AC is now set for all the dicorotrons and is discharged through the OZAC Assembly.

AC Slope (ratio): It’s the ratio between Charge 1 SI to Charge 1 SV. A DC voltage is applied to the Charge 1 shield. The amount of AC on the wires is adjusted until the ratio of Voltage to current is within specifications. The spec is actually determined by the engineers and may vary due to the amount of Dicors, belt speed, Dicor height, etc.

ESV Offsets: The process control will create and read the charge control patches in the even numbered ID Zones and measure them for charge uniformity. The Charge two (2) Shield is set to a fixed value. The patch in ID 4 will be used as a reference; ID two (2) and ID six (6) will be compared to ID four (4). The screen will display the information in bits, and each bit will represent six (6) volts.

Hi Charge Dark Decay: Dark Decay is calibrated with a charge on the Photoreceptor belt that is equal to that of a normal print mode.

Lo Charge Dark Decay: Dark Decay is calibrated with a charge on the belt that is approximately equal to that of a lighter print mode.

Dark Decay Intercept: It’s the point where the slope of HI Charge Dark Decay and LO Charge Dark decay intercepts (Y axis). The calculation is an indicator of the Dark Decay characteristics of the Photoreceptor belt at a specific point in time. Therefore a belt with a high or flat Decay slope will not satisfy the Dark Decay Intercept target.

(P) 09-213 Faults

(P) 09-213 will indicate any of six (6) different system problems that are logged in NVM. You can see them recorded in MIN 443 and MIN 444.
(P) 09-213 system faults can drive you right up a wall and leave you emotionally unstable, and a lot of times it’s not the machine but rather the tech that is making the problem even worse by not starting with the basics. I have seen it many times in the field where a tech will try to compensate for an adjustment to avoid a problem, or maybe try to cheat the system by not replacing components when they are worn out. Sometimes it’s as simple as doing the Preventative Maintenance (PM) when it is due and replacing the HSFI components when they are due. Actually I have found that before I jump into a system fault problem, I always check the HSFI screen to see what’s due or what might be close to being due.

If you are having problems running dC-951 to completion, check the following components:

1) Photoreceptor ground brush for loose, broken or missing fibers; all Dicorotrons, shields, Dicorotron wires and connectors.

2) Check or adjust the ESV height (ADJ 9-12) Charge Dicorotron height and balance (ADJ 7.9) and ROS Correction Factor (ADJ 6.3)

3) Check the dC131 [MIN] location 260 (ESV adjustment) and 285 (Patch Location).

4) Make sure the ROS Assembly is properly positioned in the rails and is not skewed.

5) Inspect the Charge Zone roller and its bearings to make sure they are turning freely.

6) Inspect the following components:

a) Ozac system and all connectors.

b) HVDC PWB Cables and connectors.

c) HVAC Output Module & Connectors (especially the white one on the HVAC Mod)

d) Dicorotrons and Dicorotron pins, connectors, shields and wires.

7) dC-314: Make sure that the proper values for both the HVDC and HVAC PWB’s are entered.

8) dC-140: While dC-140 is running, open the right processor door; after 30 seconds if any Dicorotron value is over 0.3 VDC, replace the HVDC PWB (PL1.7)

9) dC-140: Observe the (select) Dicorotron values (select) continue and if any Dicorotron Shield voltage is greater than 9.5, replace the Dicorotron(s)

10) dC-140: If any Dicorotron value is out of range, replace that Dicorotron.

11) dC-951: Run dC-951 [Xerographic Options] [Setup Initialization with fault mask] select (continue) and if any value is out of range, go to: Auto Xerographic Setup (dC-951).

12) If the problem is still preventing you to complete dC-951, perform the following:

a) IQ RAP 9-618 (PR ground)

b) IQ RAP 9-619 (ESV)

c) IQ RAP 9-621 (Patch Generator)

d) IQ RAP 9-624 (Precharge / Pretransfer Lamps)

e) IQ RAP 9-633 (dC 912 PR Uniformity)

13) Replace the following parts in the following order:

a) Photoreceptor Belt

b) HVAC PWB

c) Charge 0, 1, and 2 Dicorotrons and shields

d) HVAC Output Module

e) ESV Assembly

f) MIB PWB

g) HVDC PWB

h) MIN DIO PWB

If the problem still remains, go to RAP 6-701 With Tag P-321 (or With Out Tag P-321 RAP). The problem could be caused by the ROS Assembly when it generates a patch that is used in the process control and might be related to this problem.

It’s just as important to keep the interior clean (as well as the outside of the machine) by using your Super Sucker Vacuum Cleaner on every call. Loose dust, toner and other debris can and will affect copy quality in ways that will drive you nuts. I can be reached at: VillageCopierNY@AOL.COM if you have any comments or questions concerning the application of dC-951.