Image Quality Problems; Troubleshooting Image Quality Problems; Initial Check Items; Troubleshooting Procedure By A Particular Image Quality Problem - Minolta CF910 Service Manual

4

IMAGE QUALITY PROBLEMS

4-1.

Troubleshooting Image Quality Problems

1. Image quality problems can occur for various reasons. When troubleshooting an image
quality problem, you must first determine A. whether the cause or causes of the prob-
lem are very basic ones or highly technical ones, and B. whether the cause or causes
are attributable to the IR or PH. (Item B. can be checked by outputting a test pattern.)
This chapter is divided into two parts: "Initial Check Items" and "Troubleshooting Proce-
dure by Particular Image Quality Problem." When an image quality problem occurs,
first go through the "Initial Check Items" and, if the cause is yet to be identified, go to
"Troubleshooting Procedure by Particular Image Quality Problem."
2. When any faulty symptom is evident on the copy image, open the "Stabilizer Trouble"
screen from the "Status Confirm" menu available from the Service mode and check that
no items are marked with "NG."
4-2.

Initial Check Items

1. Installation site
• Is the correct source voltage being applied? Does the voltage fluctuate very much?
• Is the installation site hot and humid? Is it subject to steep temperature changes?
• Is the site dusty?
• Is the site subject to direct sunlight?
• Is the copier placed on a level surface?
2. Copy paper
• Is the recommended paper being used?
Load recommended paper and make copies to see if the problem persists.
• Is the paper damp?
Load new paper (newly unwrapped paper) and make copies to see if the problem per-
sists.
3. Originals
• Is the original written in light pencil?
Use the Test Chart to check the copy image.
• Is the original highly transparent or are transparencies being used?
Place a blank sheet of paper over the original when making a copy.
• Is the Original Glass or the Transport Belt of the ADF dirty or scratched?
Wipe the surface clean using alcohol if dirty and change if it is scratched.
4. "Machine Adjust" data and "State Confirm" data
• Are the settings for "Machine Adjust," "Copying Status," "Developing Status," and "Black
Toner Supply Status" in the good range?
Adjust if they are outside the good range.
• Is the value set for "Adjust" and "Level History (ATDC Ref. Value)" equal to that given on
the Adjust Label on the inside of the Front Door?
If a Developing Unit loaded with developer of another machine is to be installed, enter
the ATDC Ref. Value set for that particular machine.
5. PM parts (consumables)
• Has the cleaning/replacement time come for those PM parts (consumables) concerned
with image quality, such as PC Drum, Cleaning Blade, and corona wire?
6. Adjustment items (registration, focus, AE level, etc.)
• Of the adjustment items given in DIS/REASSEMBLY, ADJUSTMENT, are there any that
corrects the image problem by making a readjustment?
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