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Brother Printer Says "Print Unable 0B"? How to Fix It

Last updated: March 2026

The "Print Unable 0B" error on Brother printers is one of the more technical error codes you can encounter. It indicates a problem with the high voltage section, which is responsible for transferring toner to paper. While this sounds intimidating, there are several fixes you can try before considering professional repair.

Let's walk through the solutions that work most often, starting with the simplest fixes first.

In This Guide:

  • How to clean the drum unit and corona wire
  • How to inspect HV circuit boards for damage
  • When to power reset versus when to seek professional help
  • Model-specific troubleshooting steps

Fix #1: Power Reset Your Brother Printer

Turn off your printer, unplug the power cable from the back, wait 60 seconds, then plug it back in and power it on. Before diving into physical cleaning, start with a full power reset to clear temporary errors.

Steps:

  1. 1. Turn off your Brother printer using the power button
  2. 2. Unplug the power cable from the back of the printer
  3. 3. Wait for 60 seconds to allow capacitors to fully discharge
  4. 4. Plug the power cable back in
  5. 5. Turn the printer back on
  6. 6. Wait for the printer to fully initialize
  7. 7. Try printing a test page

Why This Works:

The high voltage circuit can sometimes store error states in temporary memory. A complete power cycle clears these states and allows the printer to reinitialize the high voltage system from scratch. If the error was caused by a temporary electrical glitch, this will fix it.

Fix #2: Clean the Drum Unit

Turn off and unplug your printer, open the front cover, remove the drum unit assembly, and gently wipe the drum surface with a dry lint-free cloth. Dirt, toner residue, or debris on the drum unit can interfere with the high voltage charging process.

What You'll Need:

  • Lint-free cloth or microfiber cloth
  • Isopropyl alcohol (90% or higher)
  • Cotton swabs (optional, for detailed cleaning)

Steps:

  1. 1. Turn off and unplug your Brother printer
  2. 2. Open the front cover and remove the drum unit assembly
  3. 3. Separate the toner cartridge from the drum unit (if applicable to your model)
  4. 4. Look for the green or blue drum cylinder. Do not touch it directly with your fingers
  5. 5. Gently wipe the drum surface with a dry lint-free cloth to remove loose toner
  6. 6. Use a cloth lightly dampened with isopropyl alcohol to clean any stubborn marks
  7. 7. Let the drum air dry for 5 minutes
  8. 8. Reassemble the drum unit and toner cartridge
  9. 9. Reinstall into the printer

Important:

The drum cylinder is sensitive to light and fingerprints. Work quickly in normal indoor lighting (not direct sunlight) and avoid touching the green or blue drum surface with your hands. Handle the drum only by the plastic sides.

Fix #3: Clean the Corona Wire

Remove the drum unit, locate the small blue or green slider tab on the side, gently slide it from one end to the other several times, then return it to its home position. The corona wire is a thin wire inside the drum unit that applies the high voltage charge needed for printing.

Steps:

  1. 1. Remove the drum unit from the printer (see Fix #2 above)
  2. 2. Look for a small blue or green slider tab on the side of the drum unit
  3. 3. Gently slide the corona wire cleaner tab from one end to the other several times
  4. 4. Return the slider to its home position (usually marked on the unit)
  5. 5. Reinstall the drum unit
  6. 6. Test print

Why This Works:

The corona wire is extremely thin and attracts toner dust over time. When the wire is coated with dust, it can't properly charge the drum surface. This prevents toner from transferring to paper, which the printer detects as a high voltage malfunction. Cleaning the wire restores proper electrical contact.

Fix #4: Inspect the HV Circuit Boards

Turn off and unplug the printer, remove all covers according to your service manual, locate the high voltage power supply board near the drum unit, and check for burn marks, corrosion, or loose connections. The high voltage circuit boards are responsible for generating the electrical charge needed for printing.

Steps:

  1. 1. Turn off and unplug the printer
  2. 2. Remove all covers according to your printer's service manual
  3. 3. Locate the high voltage power supply board (usually near the drum unit area)
  4. 4. Look for signs of burn marks, corrosion, or loose connections
  5. 5. Gently clean any visible dust or debris with canned air
  6. 6. Check that all connector plugs are firmly seated
  7. 7. Reassemble the printer

Caution:

Working inside the printer exposes you to electrical components. Only attempt this if you're comfortable opening electronics. If you see visible damage to circuit boards (burn marks, melted components), this is a job for professional repair. Do not attempt to fix damaged circuit boards yourself.

Fix #5: Consult Model-Specific Service Manual

Go to Brother's support website, search for your exact printer model number, look for "Service Manual" or "Advanced User's Guide" in the downloads, and follow the model-specific troubleshooting steps for the 0B error. Different Brother printer models have different internal layouts and specific troubleshooting steps.

How to Find Your Service Manual:

  1. 1. Go to Brother's support website
  2. 2. Search for your exact printer model number (found on a label inside the printer)
  3. 3. Look for "Service Manual" or "Advanced User's Guide" in the downloads section
  4. 4. Search the manual for "Print Unable 0B" or "High Voltage Error"
  5. 5. Follow the model-specific troubleshooting steps

Common Mistakes to Avoid

  • ✗Don't touch the drum cylinder directly: Fingerprints and oils can damage the drum surface and make print quality worse.
  • ✗Don't skip returning the corona wire cleaner to home position: Leaving it in the middle of its track can cause printing problems.
  • ✗Don't force anything: If a component doesn't come out easily, you might be removing it incorrectly. Consult your manual.
  • ✗Don't ignore visible circuit damage: If you see burn marks or melted components, stop and contact a repair technician.

How to Prevent This Problem

  • ✓Clean the corona wire monthly: Regular cleaning prevents buildup that causes the 0B error.
  • ✓Replace the drum unit when needed: Drums have a lifespan (typically 12,000 to 30,000 pages). Replace it when you reach that count.
  • ✓Use genuine Brother toner: Third-party toner can sometimes produce more dust, which accumulates faster on the corona wire.
  • ✓Keep the printer in a clean environment: Dusty environments cause faster buildup on internal components.

Still Seeing the Print Unable 0B Error?

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Frequently Asked Questions

What does "Print Unable 0B" mean on a Brother printer?

The "Print Unable 0B" error indicates a high voltage section malfunction in your Brother printer. This usually means the corona wire is dirty, the drum unit has issues, or there's a problem with the high voltage circuit board that charges the drum for printing. It's a hardware error that typically requires cleaning or, in rare cases, component replacement.

Can I fix the 0B error myself or do I need a technician?

Most 0B errors can be fixed at home by cleaning the drum unit and corona wire. These are user-serviceable parts designed to be maintained by the printer owner. However, if you see physical damage to circuit boards or if cleaning doesn't resolve the issue, you should contact a Brother service technician.

How often should I clean the corona wire to prevent the 0B error?

Brother recommends cleaning the corona wire every time you replace the toner cartridge, or roughly once a month for moderate use. If you print frequently (more than 500 pages per month), clean it every two weeks. The corona wire cleaner slider is built into the drum unit specifically to make this an easy regular maintenance task.

Will replacing the drum unit fix the Print Unable 0B error?

If the drum unit is very old or damaged, replacing it might fix the 0B error. However, try cleaning the existing drum and corona wire first, since this solves most 0B errors without needing a replacement. Drum units are expensive, so only replace it if cleaning doesn't work or if you've reached the drum's rated lifespan for your model.

Is the 0B error related to toner or paper quality?

The 0B error is not directly caused by paper or toner quality, but low-quality toner can contribute to the problem. Third-party toner sometimes produces more dust and residue, which can accumulate on the corona wire and drum faster. Using genuine Brother toner can help prevent frequent 0B errors.

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