OKI B432, MB472 and MB492 Print with Lines, Faded Areas or Spots: Restoring Print Quality

Last Updated on 16.08.2026 by DriverNew

Faded text, vertical white or black lines, a gray background, smeared characters, and repeating spots on printouts from an OKI B432, MB472 or MB492 can have different causes. Most often, the problem is related to a dirty LED head, low toner, damp or unsuitable paper, an incorrect paper weight setting, or damage to the image drum.

Do not start by buying consumables. First, print an internal configuration page and determine the shape of the defect. On an MFP, also compare normal printing with copying from the platen glass and through the ADF. This check helps determine whether the printing mechanism needs service or whether cleaning the scanner glass is sufficient.

Models covered by this guide

The diagnostic signs and troubleshooting procedure apply to the following monochrome printers and MFPs:

• OKI B412dn, B432dn, B432dnw and B512dn;
• OKI ES4132dn and ES5112dn;
• OKI MB472dn, MB472dnw, MB492dn and MB562dnw;
• OKI ES4172LP MFP, ES4192 MFP, ES5162 MFP and ES5162LP MFP.

The menu names and cover locations differ between B-series printers and MB-series MFPs. Therefore, the control-panel procedures and LED-head cleaning are described separately below.

Step 1. Print the internal configuration page

Do not use a Word document, PDF, or browser page for the first test. The internal configuration page is printed without the driver and helps rule out application and computer settings.

OKI B412, B432 and B512

1. Load clean plain A4 or Letter paper in the main tray.
2. Press the up or down arrow until PRINT INFO appears on the display.
3. Press OK.
4. Select CONFIGURATION.
5. Press OK to print.

OKI MB472, MB492 and MB562

1. Load clean plain paper in the main tray.
2. Press SETTING.
3. Make sure Reports is selected and press OK.
4. Select Configuration and press OK.
5. On the confirmation screen, select Yes and press OK.

If the defect is present on the configuration page, the cause is in the printer, toner, image drum, paper, or tray settings. If the configuration page looks normal but a specific document prints poorly, check the driver settings and the application from which the job is sent.

Step 2. On an MFP, distinguish a printing defect from a scanning defect

This step is required for MB472, MB492, MB562 and ES MFP models. It is especially important when vertical lines appear on copies.

1. Take a page with clearly visible text.
2. Place it face down on the large platen glass and make a copy.
3. Then feed the same page through the ADF and make a second copy.
4. Compare both copies with the configuration page.

Test result	Where to look for the cause
The line appears on the configuration page and on both copies	LED head, toner, image drum, or printing mechanism
The configuration page is clean, and the line appears only when copying through the ADF	The narrow ADF glass strip or document feed rollers
The configuration page is clean, but the defect appears on copies from both the platen glass and the ADF	The large platen glass, white document holding pad, or scanning unit
The configuration page and copies are clean, and only printing from the computer is poor	Driver, application, source file, or selected print quality

If the line appears only when using the ADF, turn off the MFP and wipe the narrow glass strip next to the large platen glass with a soft lint-free cloth. Remove even a tiny spot of correction fluid, adhesive, or toner: as the document moves, it turns into a line across the entire page. Then wipe the glass dry and repeat the copy test.

Step 3. Identify the defect by its appearance

What the printout looks like	Most likely causes	First action
Vertical white line or faded area	Dirty LED head, low toner, incorrectly installed image drum	Clean the LED head and check the toner
Dark vertical line	Damaged image drum; on copies, the glass may also be dirty	Compare the configuration page and copies, and inspect the image drum
The entire page is faded	Low toner, damp paper, incorrect paper type or weight	Check the toner and print on new plain paper
Gray background or contamination across the entire page	Damp, excessively thick, or unsuitable paper; static charge; toner or image drum	Replace the paper and check the tray settings
Identical spots repeat along the length of the sheet	Image drum or fuser unit	Measure the distance between identical spots
Toner rubs off with a finger	Paper weight is set too low, the wrong media type is selected, or the fuser unit is faulty	Set Media Type and Media Weight correctly
The edges of letters are blurred	Dirty LED head, damp or unsuitable paper	Clean the LED head and replace the paper

Step 4. Clean the LED head

The LED head is a long, narrow glass surface on the inside of the top cover. Contamination causes vertical white lines, faded areas, and blurred character edges.

Cleaning on B412, B432 and B512

1. Turn off the printer using the power button.
2. Wait until the device stops completely.
3. Press the OPEN button.
4. Fully open the top cover.
5. Do not touch the fuser unit: it remains hot after printing.
6. Locate the long glass surface of the LED head on the underside of the cover.
7. Using a soft, dry cloth, gently wipe it along its entire length from left to right.
8. Do not press on the glass or wipe it again with a dirty part of the cloth.
9. Close the top cover firmly.
10. Turn on the printer and print the configuration page again.

Cleaning on MB472, MB492 and MB562

1. Turn off the MFP.
2. Remove documents from the ADF and platen glass.
3. Lift the scanner unit.
4. Press the top cover open button.
5. Fully open the top cover of the printing mechanism.
6. Do not touch the hot fuser unit.
7. Using a soft, dry cloth, gently wipe the LED head lens along its entire length.
8. Close the top cover.
9. Lower the scanner unit.
10. Turn on the MFP and print the configuration page again.

Step 5. Check the toner cartridge and image drum

1. Check whether the control panel displays TONER LOW, TONER EMPTY, ORDER DRUM, or DRUM LIFE.
2. Turn off the device and open the top cover.
3. Make sure the blue toner-cartridge lever is turned fully toward the closed-lock symbol.
4. Hold the unit by its handle and check that the image drum is seated evenly in the guides.
5. If the toner is running low, install a new compatible cartridge.
6. Do not try to compensate for empty toner by increasing print density.
7. Inspect the visible part of the green cylinder without touching it with your hands.
8. If the cylinder has a scratch, dent, or repeating mark, replace the image drum.
9. Reinstall the unit without tilting it and close the cover.

After installing a new image drum, the first prints may sometimes look slightly lighter. Print several normal jobs and check the quality again. If nearly empty toner was transferred to the new image drum, the toner cartridge may also need to be replaced.

Step 6. Measure the interval between repeating spots

If the same spot or horizontal line repeats several times in the paper-feed direction, place the sheet on a flat surface and measure the distance between the centers of two adjacent identical defects.

Approximate interval	Likely cause	Action
94 mm	Contamination or damage to the green image drum cylinder	Inspect the image drum; replace it if there is a scratch or persistent defect
about 40 mm	Foreign material may have entered the image drum	Open and close the top cover, print several test pages; if the defect remains, replace the image drum
about 88 mm on the B series	Damage to the fuser unit	Do not disassemble the hot unit; contact a service center

These measurements are diagnostic guidelines, not a reason to disassemble the device. If the interval is different or difficult to measure, first rule out the paper, toner, and LED head.

If only a small toner particle is visible on the image drum surface and there is no scratch, it may be removed very gently with a soft, dry cloth without applying pressure. Do not use liquids, do not scrape the surface, and do not force the cylinder to rotate. If in doubt, skip cleaning and replace the damaged unit.

Step 7. Check the paper

1. Take several sheets from a new, sealed pack of plain office paper.
2. Do not use paper for testing if it has been left in an open tray for a long time or stored in a damp room.
3. Check whether the sheets are sticking together or have curled edges.
4. Load the paper with the print side facing in the direction specified for the selected tray.
5. Move the side guides against the edges of the stack without squeezing it.
6. Do not load paper above the maximum fill mark.
7. Print the configuration page again.

If the defect disappears on new plain paper, do not replace the toner or image drum. The cause was moisture, coating, thickness, or static charge in the old paper.

Step 8. Set the paper type and weight

This step is especially important if toner rubs off the sheet, printing is faded on heavy paper, or the surface has uneven gloss. The device must know the actual media type so that it can select the appropriate speed and toner-fusing mode.

OKI B412, B432 and B512

1. Use the arrow buttons to open MENUS.
2. Press OK.
3. Open TRAY CONFIG.
4. Select the tray from which the paper is actually being fed.
5. Open MEDIATYPE and select the actual media type.
6. Open MEDIAWEIGHT and select the weight that matches the paper packaging.
7. If the toner still rubs off easily, temporarily select a weight one step higher and repeat the test.

OKI MB472, MB492 and MB562

1. Press SETTING.
2. Open Paper Setup.
3. Select the tray being used.
4. Open Media Type and set the actual paper type.
5. Open Media Weight and set the actual paper weight.
6. If the toner rubs off, increase Media Weight by one step and print one test sheet.

Do not set the maximum paper weight for plain paper unless necessary. An excessively heavy setting slows printing and may cause other defects. After testing, leave the value that matches the paper being used.

If the problem appears only when printing from the computer

1. Open the printer properties and select Printing Preferences.
2. Temporarily restore the driver settings to their defaults.
3. Make sure toner-saving mode, draft quality, or excessively low density is not enabled.
4. Check that the paper size, type, and weight in the driver match the tray settings.
5. Print simple text from another application.
6. If another document prints normally, the problem is in the source file or the settings of the first application.
7. If all jobs from the computer have the defect but the internal configuration page is clean, remove the old printer queue and reinstall the appropriate OKI driver.

When a new image drum, toner, or service is required

Diagnostic result	Required action
Toner Low is displayed, and printing is faded across the full width	Install a new compatible toner cartridge
The defect repeats approximately every 94 mm, or a scratch is visible on the image drum	Replace the image drum
Toner rubs off even after the paper settings have been corrected	Have the fuser unit checked by a service center
The internal configuration page comes out completely black or blank	Reinstall the toner and image drum; if this does not help, contact a service center
The line appears only on a copy made through the ADF	Clean the narrow ADF glass and document feed rollers
The defect remains with new paper, new toner, and a known-good image drum	Provide a test page to a service center so they can check the LED head, power supply, and fuser unit

Keep the defective configuration page and mark the paper-feed direction and the distance between repeating spots on it. This sample helps identify the faulty component more accurately and avoid replacing working consumables.