Printing troubleshooting guide

Likely causes

• Print temperature set incorrectly, usually too low
• Printer pressure too low
• The ribbon itself is abnormal -- white spots, white streaks or other blemishes
• Ribbon and label mismatch, e.g. a resin ribbon on coated or rough paper
• Ribbon type incompatible with the print-head type
• Dirty print head or roller shaft, or uneven coating on the label stock

What to check and do

1. Increase the print temperature -- adjust "density" or "blackness" in your barcode software or in the printer driver properties.
2. Adjust printer pressure appropriately. Note: industrial printers have a dedicated pressure adjustment; some desktop models do not.
3. Hold the ribbon up to the light and inspect for white spots or streaks.
4. Verify the ribbon and label are compatible, e.g. a resin ribbon used on coated or rough paper.
5. Check whether a near-edge ribbon is being used in a flat-head printer, or vice versa.
6. Clean the print head and roller shaft with an alcohol swab.
7. Switch to a different label roll to rule the ribbon out.

Likely causes

• Wrinkling introduced during slitting at the factory

What to check and do

1. Wrinkles are clearly visible from the outside of the roll. If present, return or exchange the roll.

Likely causes

• The ribbon paper core is deformed and shows compression damage
• The paper core has excessive burrs and paper scraps
• The printer unwinding shaft is bent, not straight
• If the ribbon slips on the shaft, check whether the shaft spring plate has failed

What to check and do

1. Inspect the paper core for obvious deformation or a noticeably oval shape. If so, return or exchange the roll.
2. Inspect the core for paper debris or burrs, clean it and retry. If the problem persists the core is deformed -- return or exchange it.
3. Check the printer feed shaft for deformation or foreign matter. Replace or clean as needed.
4. If it still slips, replace the spring clip. If that is not the cause, the core inner diameter may be too large -- stick one or two labels on the inner wall.

Likely causes

• The ribbon carries excessive static electricity
• The printer is not grounded

What to check and do

1. Place the printer on a conductive surface where possible. If that is not feasible, fit an electrostatic discharge (ESD) device to the printer.
2. Ground the printer.

Likely causes

• The ribbon backcoat is rough or insufficient, producing high friction
• Printer pressure set too high
• The printer is configured for direct thermal mode

What to check and do

1. Press adhesive tape onto the ribbon backcoat and peel it off. If it peels with difficulty, the backcoat is coming away.
2. Reduce print-head pressure while keeping the print clear.
3. In the printer "Print Preferences", switch back to Thermal Transfer mode.

Likely causes

• The ribbon ink is not fully dried
• Excessive printer pressure
• The label stock is too thick
• The printer retracts the label during printing

What to check and do

1. Unroll a section of ribbon flat on the bench and press the ink layer gently with a finger -- check whether a significant amount transfers to your hand.
2. Reduce the print-head pressure.
3. Very thick labels can also emboss. Adjust pressure to suit the label thickness.
4. Abnormal machine settings can retract every label or every few labels, producing friction marks from the retraction.

Likely causes

• Ribbon backcoat coming away
• Damage to the end face of the ribbon roll
• Print temperature too high
• Printer pressure too high

What to check and do

1. Press adhesive tape onto the ribbon backcoat and peel it off. If it peels with difficulty, the backcoat is coming away.
2. Inspect the roll end face for notches or ragged edges, then pull the ribbon gently to see whether it breaks easily.
3. Once the print is clear, reduce the print temperature as far as you can.
4. Reduce print-head pressure to the minimum that still prints clearly.

Likely causes

• The ribbon has systematic gaps in its coating
• Localised damage on the printer rubber roller
• Systematic oil stains or adhesive bleed on the label surface

What to check and do

1. Hold the ribbon up to the light and look for repeating gaps in coverage.
2. Check the rubber roller for damage or pitting; replace it if found (this roller cannot be repaired).
3. Try a different label roll to see whether the problem clears.

Likely causes

• The ribbon itself is wrinkled
• The print head is dirty
• Broken print-head pins (or apparent breaks caused by dirt)
• Uneven print-head pressure makes the ribbon skew and wrinkle while printing
• The printer ribbon retaining plate is loose
• The ribbon transfer roller is loose, wrinkling the ribbon before the print head
• Print temperature too high, heat-wrinkling the ribbon base film

What to check and do

1. Inspect the rubber roller shaft for wear. If badly worn, replace the shaft.
2. Check the ribbon for obvious wrinkles. Try a new roll to see whether the problem persists.
3. Clean the print head with an alcohol swab.
4. First clean the area showing the white line with an alcohol swab and reprint. If the line remains, a print-head pin is broken and the head should be replaced.
5. Adjust the print-head pressure and see whether it improves.
6. Check whether the metal stop plate at the ribbon exit from the print head is loose; tighten if needed.
7. Check whether the metal transition roller at the ribbon entry to the print head is loose; tighten if needed.
8. Lower the print temperature and see whether it improves.

Likely causes

• Uneven ribbon coating (backcoat or surface coat)
• Dirty print head or roller shaft
• Uneven printer pressure side to side
• One-sided wear on the roller shaft

What to check and do

1. Inspect the ribbon coating for visible differences.
2. Clean the print head and roller shaft with an alcohol swab.
3. Even up the printer left-right pressure. Note: industrial printers have a dedicated pressure adjustment; desktop models may or may not.
4. Check the roller shaft for wear. If badly worn, replace it.