Zebra ZT231 alerts and lights: causes and fixes

CauseThe labels are loaded wrongly or miss the media sensor, the sensor is out of position, or the printer expects gap or mark labels while continuous media is loaded.

Fix

1. Open the media door and turn the printhead-open lever up.
2. Feed the labels through the slot in the media sensor and under the inner media guide, back until they touch the back of the slot. Slide the outer media guide in to the label edge.
3. Check the position of the media sensor, as Zebra's video below shows.
4. Check that Print › Print Quality › Label Type matches your labels.
5. Close the printhead and the door, calibrate and press PAUSE. See ZT231 calibration.

Video: Zebra Technologies

CauseRibbon Out: the ribbon is missing, loaded wrongly or not seen by the ribbon sensor, or the printer is set to thermal transfer while you use direct thermal labels. Ribbon In: ribbon is loaded in direct thermal mode.

Fix

1. Push the ribbon roll fully back on the supply spindle. Under the printhead, the ribbon must run all the way back, close to the inner wall of the printer.
2. Check that the coated side faces out, then close the printhead and calibrate.
3. Check Print › Print Quality › Print Type: Direct Thermal without ribbon, Thermal Transfer with ribbon. Match it in your driver.
4. Still not detected? Calibrate again or use System › Settings › Restore Defaults › Restore Printer.

Video: Zebra Technologies

CauseThe printhead is not fully closed, or the head-open sensor is faulty.

Fix

1. Turn the printhead-open lever down until the printhead locks.
2. Close the media door and press PAUSE.
3. If the alert stays, a technician needs to replace the sensor. Contact us.

CauseSomeone pressed PAUSE, or the printer paused after loading or an alert.

Fix

1. Press PAUSE once. STATUS turns steady green when the printer is ready.
2. To clear stuck jobs first: while paused, press CANCEL once to drop the next label format, or hold it for 2 seconds to drop all of them.
3. If it pauses again, use the fix for the message on the display.

In Peel Off mode the printer waits after each label until you take it. That is normal.

CauseSteady yellow: the printhead is too hot. Flashing yellow: the printhead is near its lower temperature limit, or the main logic board or power supply is too hot.

Fix

1. Too hot: let it cool; printing resumes by itself. If it repeats, lower the print speed or give the printer more space.
2. Too cold: keep printing while the head warms up. If the alert stays, the room is too cold (at least 5 °C for thermal transfer).
3. "Head Under Temp" alternating with "Head Thermistor Fault" means a cable or printhead fault. Contact us. The head may still be hot.

CauseSTATUS, PAUSE and DATA red ("Head Identification Failed"): the printhead is not a genuine Zebra printhead or has a fault. The ZT231 works only with genuine Zebra printheads. STATUS flashing red: the printer cannot read the printhead's resolution.

Fix

1. Switch the printer off and on again.
2. If the error returns, the printhead needs replacing. Contact us.

"Replace Printhead" means the head is nearly worn out. "Head Element Out" means a dot has failed; replace the head if that affects your labels.

CauseLabels are loaded wrongly, stuck in the path or wrapped around the platen roller. On cutter models, the cutter blade is stuck in the label path.

Fix

1. Paper Jam: open the printhead, remove torn labels and peel labels off the platen roller carefully. Clean off adhesive with isopropyl alcohol and reload.
2. Cutter Error: switch the printer off and unplug it. Check the cutter for label pieces and clean it as described in the Zebra ZT231 user guide.

CauseDarkness or speed doesn't suit the supplies, the printhead is dirty, label and ribbon don't match, or printhead pressure is uneven. The driver can override printer settings.

Fix

1. Run the Print wizard with Print Quality Assistance, or set Darkness and Print Speed under Print › Print Quality. Use the lowest darkness that prints well; slower speeds help.
2. Switch off, remove ribbon and labels, and wipe the brown strip on the printhead end to end with a swab and 99.7 % isopropyl alcohol. Clean the platen roller while turning it by hand.
3. One side lighter: turn the printhead pressure dial on that side one step higher (inside dial for the left side, outside dial for the right side). The dials go from 1 to 4.
4. Long, blank streaks across several labels mean a damaged printhead element. Contact us.

Zebra advises cleaning the printhead after every ribbon roll, or every label roll in direct thermal mode.

CauseRibbon loaded wrongly, wrong darkness or speed, uneven printhead pressure, or labels wandering sideways.

Fix

1. Reload the ribbon so that it runs straight and as far back as it can go under the printhead.
2. Lower the darkness, or run the Print wizard.
3. Slide the outer media guide in until it touches the label edge.
4. Set the pressure dials to Zebra's starting points: both on 2 for labels 89 mm or wider, inside 2.5 and outside 1.5 for 76 mm, inside 3 and outside 1 for 51 mm.
5. Check the ribbon tension: both spindles must use the same setting. Normal tension (end caps pulled out until they click) suits most jobs; low tension (both pushed in) is for narrow ribbon or ribbon that scuffs or stalls.