Xerox WorkCentre 7120 style Tech Info Sheets Part 2: Copy Quality Adjustments

Xerox WorkCentre 7120, 7125, 7220, 7225

Last month we took a first glance at the Xerox WorkCentre 7120 Style, one of Xerox’s mid-sized, full-color copiers/MFPs. We covered the supply items and listed the more-valuable fault codes, briefly touching on how to use the diagnostic function “NVM Read/Write” to clear the codes after you repair the underlying cause of the faults.

This month, we’ll learn more about how to use the diagnostic mode specifically to make adjustments to the color balance, color registration and overall copy quality.

7225 Copier

Before we get started, there’s something important to follow up on from last month’s article. The code listing was for the WC-7120/7125 models, but the list applies also to the 7220/7225 models if you are aware that all of the fault codes will simply need to start with “3” instead of “0.” For example, instead of the fault code 092-315 as seen on a 7120 machine, you’d see fault code 392-315 if you are working on a 7220 with the same problem.

Let’s begin with the basics of getting into, and navigating, the Diagnostic Mode. As is true with most Xerox photocopiers in this weight class, the diagnostic features are extensive. There are some things which are best left untouched unless you’re an authorized dealership with a PWS laptop and the software for backing up settings and reloading firmware. I’ve made mention of those few functions you should avoid entirely in the Diagnostic Menu listed below.

How to get into the Diagnostics Menu:

1. Hold down “0” for at least 5 seconds, then while still holding “0,” press the “Start” button.
2. At the prompt, enter the default passcode “6789,” then touch “Confirm”. The top right of the control panel will show “Service Rep” on an orange tab.
3. Press the “Machine Status” button and choose the “Tools Tab”.
4. With “System Settings” selected in the left column, choose “Common Settings,” then scroll down in the right column and choose “Maintenance/Diagnostics.”

Exiting Diagnostics:

Close any open menus and then choose “Exit.” Choose “Exit -Keep Log” so you can still go back to see recent faults if you need to.

The Maintenance/Diagnostics Menu includes the following options:

• Quick Setup [for things like IP Address Settings]
• Software Options
• NVM Read/Write [for some adjustments and for clearing some of the fault codes]
• Initialize Hard Disk [never do this unless the customer is ok with losing all of their data and settings; a better way to clear a corrupted print job is to use one of the Special Boot Modes—refer to the previous ENX article 7120 style Tech Info, Part 1]
• Print Test Patterns [very helpful for troubleshooting copy quality issues]
• Delete All Data [never use this, as it initializes many of the machine settings and will result in the loss of the factory setups for System Registration, Image Quality and Scanner Setups]
• Initialize NVM [never use this feature unless you know exactly what you’re doing; this should only be used by people who have the ability to restore the machine from a backup]
• IO Check [here you’ll find “Component Control” for testing motors and sensors etc.]
• Sub System
• Adjustments/Others [Machine ID and Billing settings for synchronizing logic boards; you’ll also find the HFSI (High Frequency Service Item) Counters]
• Registration [adjustments for both registration of colors and registration of the image to the paper can be found here]
• Faults [choose “Shutdown History” and then “Last 40 Faults” to view the most-recent faults]
• Max Setup [adjustments for toner concentration, Scanner Calibration, & 2nd BTR Transfer Voltage]

Note that if copy quality is off and you’re at a high elevation (over 1,000 ft. above sea level), there is a way to adjust the charge roll voltage to suit various elevation ranges. That adjustment is designed to help correct some light copy problems which can happen as the charge voltage increases with higher elevations.

Before we get into the adjustments which are only available from the Diagnostic Mode, let’s have a look at a great tool which is available in the Administrator’s “Customer Tools,” as well as in Diagnostics Mode.

Color Calibration:

Procedure:

1. Go into Diagnostic Mode or login as the Administrator (default username = “admin” and the default password is “1111”). If the default password for admin doesn’t work then you will need to get the password from the customer, or go into diagnostic mode to run this adjustment.
2. Press “Machine Status” and touch the “Tools” Tab.
3. Select “Setup & Calibration” and then in the Group column, choose “Calibration”
4. Choose the type of job you want to calibrate colors for and select the “Paper Tray” you have loaded for printing out the Calibration Test Page and touch “Save.”
5. Select “Target” and choose the calibration type (you can choose “Copy & Print Jobs,” ”Copy Jobs Only,” or “Print Jobs Only”), then touch “Save.”
6. Press the “Start” button and a calibration test page will print out along with instructions.
7. Place the calibration test page face down on the platen glass with the magenta squares on the left side of the glass, and press the “Start” button. The machine will display if the calibration was successful or unsuccessful.
8. Go back and repeat these steps for each required Job Type and Calibration Type.

Next, let’s concentrate on the adjustments available in the “Max Setup” menu.

ATC Sensor Setup (ATC=Automatic Toner Concentration): Here’s a way to perform an ATC Sensor Setup immediately after installing a new drum/developer cartridge with a known toner density (a new OEM Drum Cartridge comes with the proper toner concentration). Normally you should not need to do this every time you install a new drum cartridge—it should only be done if the concentration seems to be going “off” after a new cartridge was recently installed. Unfortunately, since this adjustment requires a new cartridge, you’d need to have another new cartridge again to do the adjustment.

Procedure:

1. From the Maintenance / Diagnostics screen, choose “Max Setup”
2. Select “Default Developer ATC Setup”
3. Select the “On” button for the color or colors you need to set up and touch “Start.”
4. When the machine is done, it will show the ATC measurement Value, the ATC Target Value and the results (NG means no good—in those cases, double check the ATC Sensor on the drum/developer cartridge and the wiring and connector leading to the sensor).

Toner Density Adjustment (Tone Up/Tone Down): This is useful for a one-time increase or decrease of toner concentration in a particular color. This is particularly helpful if you just solved a Toner Dispense problem which caused light copies in one or more colors as the toner density has dropped too low.

Procedure:

1. From “Maintenance/Diagnostics,” choose “Max Setup,” followed by “Adjust Toner Density.”
2. Choose the “Number of Sheets” using the up and down arrows (2-3 pages up or down are recommended).
3. If you enter a positive number, this will increase the TC (Toner Concentration). The machine will print out blank pages while toning up.
4. If you enter a negative number, it will instead decrease the TC. The machine will print solid-area coverage patches to help pull toner out of the developer unit, while not adding more toner during the adjustment cycle.
5. Always adjust only one color at a time.
6. After the adjustment, the machine will display the “TC Measurement” and the “TC Target.” Repeat the steps as needed till you are within +/-30 of the TC Target.

Copy Mode Color Balance Adjustment: Note that the Service Manual recommends only using this adjustment if there is a strong customer complaint regarding color rendering in copy mode.

Procedure:

1. Get a good full color test pattern or a good example of a full color print and make two copies.
2. From “Maintenance/Diagnostics,” choose “Max Setup,” followed by “Color Balance Adjustment.”
3. Compare the copies you made to the original. For each color and for each density range (low density, medium density & high density), assign a number from -4 to +4 (negative numbers will result in lighter copies, and positive numbers mean darker ones).
4. Press the “Start” button to save the new adjustment values.
5. Exit Diagnostic Mode and then turn the machine off and back on to reboot it fresh. Make 2 new copies and compare them to see if you got the desired results. You may need to try this procedure several times to get the copy quality to the point where your customer is satisfied.

Scanner/IIT (Image Input Terminal) Calibration: You can do a White Reference Adjustment from here. The White Reference Strip is located on the underside of the platen glass. Before you begin, you’ll want to first clean the optics, including the white reference strip, the platen glass and the mirrors. Note that in this same menu, there is also an adjustment available to run a “CCD Calibration,” but that would require the use of a special test pattern (part #: 82E13120).

White Reference Adjustment Procedure:

1. Place 10 sheets of clean white paper on the document platen glass.
2. From “Maintenance/Diagnostics,” choose “Max Setup,” followed by “IIT Calibration.”
3. Choose “White Reference Adjusment” and touch “Start” on the screen.

Color Registration Adjustment: This will help line up the colors when they stray. Assuming things are mechanically correct and the MOB sensor (Marks On Belt Sensor) is OK, this adjustment is designed to correct misaligned colors.

Procedure:

1. From Diagnostic Mode, choose “Registration.”
2. Select “Registration Control Setup Cycle” and press “Start.”
3. The color shift should be corrected automatically.

Happy summer, everyone. I hope the adjustments go well for you, and you get the stunningly colorful copies your customers crave out. Hope to see you all reading again next month.