Tips for Maintaining Good Copy Quality for the DocuColor 250 Style

For: (DocuColor) DC- 240, 250, 242, 252, 260, (WorkCentre) WC- 7655, 7665, 7675, 7755, 7765, 7775, Xerox Color 550, 560, 570, C60, C70, DCP700, 700i, 770, and C75, J75

New models based on the superbly designed DC250 style just keep on coming. The newest models are the Xerox Color C60 and C70. All of these machines are capable of producing truly excellent print and copy quality. The key is regular maintenance, cleaning, and maybe an occasional adjustment. This month we’ll go through some of the best practices for keeping these machines working well. We’ll also check out some of the tools available to you for adjusting the image quality.

Photo #1: Remove a small cover (1 screw)

First off, cleanliness is extremely important. The best way to keep these machines clean is to remove and clean off the exhaust/dust filter frequently. The recommendation is that anytime you have to replace a drum cartridge, it’s worth the extra time to remove this large filter (see Photos #1 & 2) and vacuum it off.

Replace it periodically when it gets clogged up. In the original parts listings, the “Ozone Filter” was sold as an assembly (053K91940). Later on they split this item into the two filters, which are now sold separately. The exhaust/dust filter is the main box-like filter 053K91902 (DC250EDF), and then there’s the black carbon ozone filter 053K91910 (DC250OF), which is tucked into the bottom of this same box.

Photo #2: Slide the Filter Assembly out. Clean the dust filter (on top) thoroughly.

If you allow the dust filter to get too dirty, the airflow in the machine slows down, and the entire copier gets contaminated with toner and paper dust. Keeping the filter clean will add life to just about every component in the machine; in particular it helps maximize the yields on the drum cartridges. Toner contamination in the machine can also cloud the laser slit glasses causing light copy quality. It can also pollute the inside of the IBT belt, causing IBT Home Sensor Failure faults, which can be a bit of a nuisance.

Another important thing to watch are the Mylar seal blades on the top covers of the developer units. These mylars are easily damaged, and are known to curl over time. Eventually they can allow toner to puff out into the machine. If you see that these seal blades are losing their integrity, you can order replacement developer seal blades (DC250DSBK).

Once you clean up the machine and its dust filter, you’ll want to check the condition of all of the primary consumable components. Check the three color drum cartridges and the one black drum cartridge, the developer units and the developer, the second BTR assembly (transfer roll), the IBT belt, the belt cleaning assembly, and the fuser. Check for any excessive wear or damage and repair as needed.

With all that taken care of, there is one adjustment called “Color Gradation” available to the System Administrator which should be done on a regular basis. It’s recommended that the machine’s administrator should do this anytime they replace a drum cartridge or notice a change in color density. This’ll help keep the copy and print quality looking its best.

Auto Gradation Procedure:

1. Log in as System Administrator (press the ‘Log In / Out’ button). 
   For DC240/242/250/252/ 260: The default username is ‘11111’ (five 1’s), & the default password is ‘admin’.
   For 550/560/570, WC-7655/7665/7675, WC-7755/7765/7775, J75/C75: If prompted for a username, the default is ‘admin’ (older software only asks the password), & default password is ‘1111’ (four 1’s).
   For DCP700: Default username is ‘11111’ (five 1’s), & default password is ‘x-admin’.
2. Select ‘System Settings’ twice, followed by ‘Common Settings’.
3. Choose ‘Image Quality Adjustments’, and then ‘Auto Gradation Adjustment’.
4. Choose from the three available screen types (‘Copy Job’, ‘Print Job 1’, & ‘Print Job 2’).
5. Load good white paper (the recommendation is for 98 brightness or brighter) in a paper tray and then select ‘Paper Supply and Target’ and choose the tray you just loaded.
6. You can select ‘Target’ to set a particular area for applying the adjustment to.
7. Press the ‘Start’ button on the console and an adjustment chart will print out.
8. Next place the adjustment chart on the document glass with the magenta color patch against the left edge of the glass and with five sheets of clean white blank paper on top of it.
9. Press the ‘Start’ button once again and the calibration will happen. It takes about 30 seconds or so, till you see either a completion message or an error message.
10. Go back to step 4 and repeat the process for the other two available screen types.

The next thing that you as a technician would be concentrating on would be the MAX Setup / Adjustments. To reach the Max Setup / Adjustments menu, you’ll need to enter UI (User Interface) Diagnostic Mode:

Entering UI Diagnostic Mode:

For DC240/242/250/252/260, 550/ 560/570/C60/C70, DCP700/700i/770, J75/C75: Hold down the ‘0’ button for 5 seconds and then, while still holding the ‘0’, press ‘Start’. A password prompt will show up. Use the default password ‘6789’ followed by ‘Confirm’.
For most WC-7655/7665/7675’s (some early ones with firmware which begins with .032 instead of .033 work like the DC250 above) and for any of the 7755/7765/7775: Hold down together ‘*’, ‘#’, & ‘Stop’ for about ten seconds, until the password prompt shows up. Then enter ‘6789’ followed by ‘Confirm’.

Next, once you’re in:

For DC240/242/250/252/260: Press the ‘Log In / Log Out’ button to see the UI Diagnostics screen.
For 550/560/570/C60/C70, DCP700/700i/770, J75/C75: Press instead the ‘Machine Status’ and choose ‘Tools’. For any of these models you will next choose ‘System Settings’, then ‘Common Settings’, followed by ‘Maintenance / Diagnostics’. Here you’ll find the main diagnostics menu. Touch the button for ‘MAX Setup’.
For WC-76xx and WC-77xx families: These models will reboot into the UI Diagnostics screen. You will only need to choose the ‘Adjustment Tab’ (this replaces the ‘MAX Setup’ in these models). Then you will choose the appropriate “dC” number and touch ‘Launch Routine’.

Max Setup (Adjustments) Menu:

• Procon ON/OFF Print (dC937): This is a rather detailed process that checks for problems in the sensing and color logic. You’ll need the service manual on-hand to perform this particular test.
• IIT Calibration (dC945): The IIT (Image Input Terminal) is the scanner. This adjustment has two parts—setting the White Reference Level, and CCD Calibration. Read below.
• In/Out Manual Setup (dC931): Another complicated adjustment that corrects slight problems with inconsistencies for each color when comparing the density from front (outboard) to rear (inboard). Here again if this adjustment is necessary, you’ll need to have the service manual on-hand to do this properly. The book tells us the change is very slight.
• ATC Sensor Setup (dC950): Normally this adjustment need only be done if you’re replacing one of the developer units (and therefore the ATC Sensors which are mounted on the DV Units). This allows you to tell the machine the sensor settings. There are 3-digit codes that are printed on small stickers on the ATC Sensors themselves. The labels have 3-digit codes that start with a zero.
• TRC Adjust (dC924): Manual toner density default adjustments. This adjustment you’ll not want to use unless the rest of the adjustments are not getting the job done. This changes the center-point for the Auto Gradation process. You’ll type in the new center-point value for the color you want to change. The range for each is from -255 to +255 and the default value is ‘0’.
• Tone Up/Down (dC991) (Toner Density): This adjustment is to help tone up or tone down a particular color which has been depleted or over-toned, due to a toner dispense problem or some other xerographic issue. Make sure you’ve already solved the problem that caused the in-balance first. Read below for details on this adjustment.
• Color Balance (dC919): This adjustment only affects copy mode. It gives you a way to adjust the density of each color at the high density, mid density and low density settings beyond what the Auto Gradation will do. Read below for more details.

IIT (Scanner) Calibration (dC945):

First clean the Scanner / IIT (Image Input Terminal). Use a lintless clean cloth with lens and mirror cleaner. Pay special attention to the white reference strip under the platen glass. After allowing time for it to cool off, you can clean the exposure lamp using a clean cloth with isopropyl alcohol.

Next enter diagnostic mode and go to dC945 IIT Calibration (in the MAX Setup menu or under the Adjustment Tab). Place ten sheets of bright white paper (98 brightness or brighter) on the platen glass. Choose the ‘White Reference Adjustment’ button and press ‘Start’. Then choose the ‘CCD Calibration’ button and press ‘Start’ again. Place the color test pattern on the glass and then touch ‘OK’ on the screen. Voila! Your optics are all set now.

Tone Up / Down (Toner Density Setup) (dC991):

First solve whatever mechanical or xerographic problem caused the toner density in a particular color to be thrown off. From the adjustment screen, select ‘Read’. The machine will show on display the target values for the ATC (Automatic Toner Concentration), and the value that the machine is reading for each color. If any of the values are off by more than 25 bits for Cyan, Magenta or Yellow (or 50 bits for Black), then you’ll want to perform the adjustment. You’ll enter a number between -99 and +99 where positive numbers will result in a decrease in toner concentration, and negative numbers will increase the toner concentration. The number you enter represents the number of tone up or tone down cycles that the adjustment will run. You can run the adjustment repeatedly as needed until the target and the measured value match each other.

Color Balance (Copy Mode) (dC919):

For this adjustment, you can choose a value between -4 and +4 for each of three density settings on each color (high density, mid density, and low density). Here negative numbers result in lightening of the parts of the image that are showing the particular densities. The higher the number, the darker the image will become. Press ‘Save’ on the screen once you have all of the numbers where you’d like them, then choose a paper tray and press ‘Start’. The machine will run a copy for you to inspect and to show your customer. You can make more changes if the outcome doesn’t look right. Once it all looks good, you can press ‘Save’, and then perform a “Call Closeout” to lock the new settings in.

Fiery Calibration:

The final aspect of print quality adjustments is done from the Fiery using a special tool called a Densitometer such as the X-rite DTP32, or DTP41. Here you’ll want to read up on the procedure by going to support.xerox.com, choosing your correct model and then typing in the keywords “Fiery Calibration”. The Xerox support end of their website is really great!

That’s it in a nutshell! I hope it helps lead you to the gorgeous colors you’re looking for. Happy repairs all!