Zebra ZT231 troubleshooting guide: errors, faults and fixes

Short answer: On the ZT231, the background colour of the home screen reflects the printer's status. According to Zebra, a red or yellow background generally blocks printing until the problem is resolved; a green message is informational and usually clears by itself.

Likely cause

The Zebra guide states that a change in the home screen background colour may require action on your part to return to the ready state.

What to do

1. Touch the icons in the bar at the top of the home screen to read the error, alert or information message.
2. Look up this message in the lookup table and open the matching entry.
3. Once the problem is resolved, check that the STATUS light returns to solid green: the printer is ready.
4. To print the last label again, touch Reprint on the home screen. If the button does not appear, no format is available for reprinting.

The ZT231's control panel combines a colour touch display, five lights (STATUS, PAUSE, DATA, SUPPLIES, NETWORK) and three buttons: PAUSE (starts or stops the printer), FEED (feeds one blank label) and CANCEL (when paused, one press cancels the next format; holding it for 2 seconds cancels them all).

Sources: Alert and Error States (opens in a new window) · Control Panel (opens in a new window) · Indicator Lights (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: The ZT231 guide gives two explanations: the printhead is not fully closed, or its head-open sensor is malfunctioning. Close the printhead completely; if the alert stays on the display, the sensor must be replaced by a technician.

Likely cause

Printhead not completely closed, or head-open sensor not working properly.

What to do

1. Close the printhead completely.
2. Check that the alert clears and the STATUS light returns to solid green.
3. If Head Open is still displayed even though the printhead is properly closed, the head-open sensor is at fault.

When to call a technician: if Head Open is still displayed with the printhead closed, Zebra specifies replacement of the head-open sensor by a service technician.

Sources: Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Indicator Lights (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: Zebra gives three causes: media incorrectly loaded, media sensor incorrectly positioned, or printer set for separate labels when the roll is continuous. Reload the media, check the sensor and the label type, then run a calibration.

Likely cause

Media missing or incorrectly loaded; media sensor misaligned; printer configured for non-continuous media when continuous media is loaded.

What to do

1. Reload the media following the “Loading the Media” section of the guide, according to your mode (tear-off, peel-off, cutter…).
2. Check the position of the media sensor.
3. Check the label type in Menu > Print > Print Quality > Label Type: Continuous, Gap/Notch or Mark.
4. Check the selected sensor in Print > Sensors > Sensor Type: Transmissive for most media, generally Reflective for black mark media.
5. Run a calibration (see the calibration entry).

With continuous media, the guide states that the label format must specify a label length (^LL command).

Sources: Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Indicator Lights (opens in a new window) – Zebra ZT231/ZT231R user guide · Print Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: The media is getting stuck somewhere along its path: incorrectly loaded, stuck to a part or wrapped around the platen roller. Carefully remove the jammed labels and, if adhesive remains on the platen roller, clean it.

Likely cause

Media problem in the media path: labels incorrectly loaded, stuck to parts in the path or wrapped around the platen roller.

What to do

1. Look for incorrectly loaded media or labels stuck to parts of the media path.
2. Check whether media has wrapped around the platen roller; remove the labels carefully.
3. If adhesive remains on the platen roller, clean it (“Cleaning the Printhead and Platen Roller” procedure in the guide).
4. Reload the media.

On a ZT231 fitted with the linerless option, a linerless cutter jam or media wrapped around the platen roller is shown as Ribbon Out: see the Ribbon Out entry.

Sources: Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) (official documentation).

Short answer: In thermal transfer mode, the sensor does not see the ribbon: ribbon missing or not properly engaged, sensor blocked by the media, or printer set to thermal transfer with direct thermal labels. Reload the ribbon and calibrate; if that is not enough, restore the printer settings.

Likely cause

The Zebra table lists: ribbon not loaded or incorrectly loaded; ribbon sensor not detecting the ribbon; media blocking the ribbon sensor; ribbon correctly loaded but not detected; direct thermal labels while the printer expects ribbon in thermal transfer mode.

What to do

1. Reload the ribbon (“Loading the Ribbon” section). Under the printhead, it must go all the way back, close to the inner wall (firewall), so that it passes in front of the sensor.
2. Calibrate the printer (see the calibration entry).
3. If the ribbon is still not detected even though it is correctly loaded, recalibrate or restore the default values: Menu > System > Settings > Restore Defaults, PRINTER option.
4. With direct thermal labels, set Print > Print Quality > Print Type to Direct Thermal.
5. Conversely, if the printer does not report the end of the ribbon, it was calibrated without ribbon or with incorrectly loaded ribbon: reload it, then recalibrate.

With the linerless option, Ribbon Out can also indicate a linerless cutter jam or media wrapped around the platen roller. The guide then refers to the PAPER ERROR recommendations in the “Linerless Printing or Cutter Issues” section.

Sources: Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Indicator Lights (opens in a new window) – Zebra ZT231/ZT231R user guide · Ribbon Issues (opens in a new window) – Zebra ZT231/ZT231R user guide · System Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: Ribbon is loaded while the printer is set to direct thermal. With direct thermal labels, remove the ribbon: Zebra states that this message does not affect printing. With thermal transfer labels, set Print Type to Thermal Transfer.

Likely cause

Ribbon loaded, printer set to direct thermal mode.

What to do

1. Direct thermal labels: remove the ribbon, which is not needed.
2. If the message persists with no ribbon in the printer, calibrate it (see the calibration entry).
3. Thermal transfer labels: set Print > Print Quality > Print Type to Thermal Transfer.

Sources: Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Indicator Lights (opens in a new window) – Zebra ZT231/ZT231R user guide · Print Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: The printhead is overheating. Let the printer cool down: printing resumes by itself as soon as the printhead elements return to an acceptable temperature. If the alert comes back often, move the printer or reduce the print speed.

Likely cause

Printhead temperature too high.

Caution: HOT SURFACE: according to Zebra, the printhead can be hot enough to cause severe burns. Let it cool before touching it.

What to do

1. Let the printer cool down; printing resumes automatically.
2. If the error persists, move the printer.
3. Reduce Print Speed (Menu > Print > Print Quality).

Sources: Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Indicator Lights (opens in a new window) – Zebra ZT231/ZT231R user guide · Print Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: If the printhead is simply approaching its lower temperature limit, keep printing: it will warm up. If the alert persists, the room is too cold or the printhead is at fault: data cable incorrectly connected, or a faulty thermistor that means the printhead must be replaced.

Likely cause

Zebra lists: printhead temperature close to its lower operating limit; printhead data or power cable incorrectly connected; faulty printhead thermistor. The indicator lights page states that a flashing yellow STATUS light can also indicate overheating of the main logic board or the power supply.

Caution: HOT SURFACE: according to Zebra, the printhead can be hot enough to cause severe burns. Let it cool before touching it. Zebra states that an incorrectly connected printhead data or power cable can cause these messages.

What to do

1. Keep printing while the printhead reaches its operating temperature.
2. If the message is still displayed, move the printer to a warmer location.
3. If the ambient temperature is not the cause, the printhead must be properly reconnected.
4. If the printhead thermistor is faulty, replace the printhead.

Sources: Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Indicator Lights (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: The printer does not have enough memory for the requested function. Simplify the label format or the settings, in particular by setting the print width to the actual width of the label, and check that the data is not addressed to a device that is not present.

Likely cause

Not enough memory to carry out the requested function.

What to do

1. Adjust the label format or the printer settings to free up memory.
2. Set the width in Menu > Print > Print Quality > Label Width (Dots) to the actual width of the label rather than the default value.
3. Check that the data is not being sent to a device that is not installed or is unavailable.

When to call a technician: if the message persists, Zebra advises calling a service technician.

According to the Print menu, a width that is too large wastes memory and may print beyond the label; one that is too narrow truncates the format.

Sources: Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Print Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: On the touch display, open Print > Sensors > Manual Calibration, touch Start Calibration and follow the prompts, touching Next at each step. Shortcut: hold PAUSE + FEED + CANCEL for 2 seconds. At the end, press PAUSE to resume printing.

Likely cause

Zebra advises calibrating as soon as there is a problem with the printed output. If automatic calibration fails, the guide lists: media or ribbon incorrectly loaded, sensors not detecting the media or ribbon, dirty or incorrectly positioned sensors, wrong media type, printer set to continuous or not calibrated for the media in use.

Official manual calibration procedure

1. Check that the media and ribbon are correctly loaded, and that the sensors are clean and correctly positioned.
2. Check Label Type (Continuous, Gap/Notch or Mark) in Print > Print Quality, and Sensor Type (Transmissive or Reflective) in Print > Sensors.
3. On the touch display, go to Print > Sensors > Manual Calibration.
4. Touch Start Calibration.
5. Follow the printer's prompts: carry out the requested action, then touch Next to go to the next step.
6. When calibration is complete, press PAUSE to exit pause mode and allow printing.

Zebra asks you to follow the procedure exactly in the order shown. To cancel at any step, press and hold CANCEL. To diagnose detection, print a sensor profile: Print > Sensors > Print: Sensor Profile, or hold FEED + CANCEL at power-up. The Power Up Action and Head Close Action settings (System > Settings) determine what the printer does at power-up and when the printhead is closed: CALIBRATE, FEED, LENGTH, NO MOTION or SHORT CAL.

Sources: Performing Manual Sensor Calibration (opens in a new window) · Print Menu (opens in a new window) · System Menu (opens in a new window) · Miscellaneous Issues (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: According to Zebra, the printer is not calibrated for the media, the media type is set incorrectly or the platen roller is dirty. Set Label Type, clean the platen roller, then calibrate.

Likely cause

The “Printing or print quality problems” table lists: printer not calibrated, incorrect label format, separate labels used in continuous mode, dirty platen roller, media guides incorrectly positioned, media or ribbon incorrectly loaded, printhead pressure set incorrectly, media not meeting specifications.

What to do

1. Set Label Type to match your media (Gap/Notch, Continuous or Mark), then calibrate (see the calibration entry).
2. Check the label format sent by your software.
3. Clean the printhead and the platen roller.
4. Reposition the media guides, then reload the media and the ribbon.
5. Check the media: the gaps or notches between labels must measure 2 to 4 mm and be evenly spaced.
6. To correct a constant image offset, use Vertical Label Offset or Horizontal Label Offset in Print > Image Adjust.

Sources: Printing or print quality problems (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Print Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: Zebra links ribbon wrinkling to three settings: ribbon loading, burn temperature (darkness and speed) and printhead pressure. Reload the ribbon, reduce the darkness or speed, and bring the pressure down to the minimum needed.

Likely cause

Ribbon incorrectly loaded; incorrect burn temperature; incorrect or uneven printhead pressure. The print quality table also attributes fine grey diagonal lines on blank labels to wrinkled ribbon.

What to do

1. Reload the ribbon correctly.
2. Set the darkness to the lowest level that gives good quality and, if necessary, lower the speed: Menu > Print > Print Quality.
3. Set the printhead pressure to the minimum that gives good print quality.
4. If you are able to, check that the printhead and the platen roller are correctly installed.

When to call a technician: if the printhead or the platen roller appear to be incorrectly installed and you cannot check this, Zebra refers you to a technician.

Sources: Ribbon Issues (opens in a new window) – Zebra ZT231/ZT231R user guide · Printing or print quality problems (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) (official documentation).

Short answer: The darkness is too high, or the ribbon is coated on the wrong side. Lower Darkness (and possibly the speed), clean the printhead and the platen roller, and change the ribbon if it is not coated on the right side.

Likely cause

Darkness set too high; ribbon with an unsuitable coated side.

What to do

1. In Menu > Print > Print Quality, lower Darkness (0.0 to 30.0) to the lowest level that gives a good print, and lower the speed if necessary.
2. Clean the printhead and the platen roller.
3. Replace the ribbon with one coated on the correct side.

The Print menu points out that excessive darkness can also blur the image, make barcodes unreadable and wear the printhead prematurely.

Sources: Ribbon Issues (opens in a new window) · Print Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: The media guide is set incorrectly, the printhead pressure is unsuitable, or previous labels were torn off incorrectly. Adjust the guide so that it just touches the edge of the media, and pull labels down and to the left to remove them.

Likely cause

Media not feeding straight (media guide, printhead pressure); previous labels torn off in the wrong direction, which makes the media slide sideways.

What to do

1. Adjust the media guide so that it just touches the edge of the media.
2. If that is not enough, check the printhead pressure.
3. To remove a label, pull it down and to the left: the tear-off bar helps cut the liner. Pulling upwards, or down and to the right, can shift the media sideways.
4. If the label does not stop in the right place on the tear-off bar, adjust Print > Image Adjust > Tear Line Offset (-120 to +120).

When to call a technician: if the media still drifts after adjusting the guide and the pressure, Zebra advises calling a technician.

Sources: Ribbon Issues (opens in a new window) – Zebra ZT231/ZT231R user guide · Printing or print quality problems (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Print Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: Zebra cites incorrectly set darkness or speed, a dirty printhead, incorrect printhead pressure or an unsuitable label and ribbon combination. Clean the printhead and the platen roller, then set the darkness to the lowest level that gives good quality in Menu > Print > Print Quality.

Likely cause

The ZT231 print quality table lists: incorrect darkness or speed (the driver or software can change them), dirty printhead, incorrect or uneven printhead pressure, unsuitable label and ribbon combination, media or ribbon not designed for high speed, a format that scales a non-scalable font. The Head Maintenance Needed message indicates that the printhead needs cleaning.

Caution: HOT SURFACE: according to Zebra, the printhead can be hot enough to cause severe burns. Let it cool before touching it.

What to do

1. If the display shows Head Maintenance Needed, or if the printhead is dirty, clean the printhead and the platen roller following the “Cleaning the Printhead and Platen Roller” procedure in the “Routine Maintenance” chapter of the guide.
2. Run the Print Wizard again, as described in the “Running the Print Wizard and Printing a Test Label” section.
3. Set Darkness to the lowest level that gives good quality: too high, it blurs the image, burns the ribbon and wears the printhead prematurely.
4. Lower Print Speed (2 to 14 ips): a slower speed generally improves quality.
5. Check that your driver or labelling software is not imposing other speed or darkness values.
6. Set the printhead pressure to the minimum needed (“Adjusting the Printhead Pressure” section).
7. If the fault persists, try different media or a different ribbon; an authorised Zebra distributor or reseller can advise you.

According to Zebra, print that is too light or too dark on only one side of the label indicates uneven printhead pressure. With thick labels, the guide also recommends reviewing the pressure.

Sources: Printing or print quality problems (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Print Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: The barcode is out of specification because the darkness or printhead pressure is set incorrectly, or the blank area around it is too narrow. Run the Print Wizard again, adjust darkness and speed, and leave at least 3.2 mm of blank space around the barcode.

Likely cause

Barcode out of specification (incorrect darkness or insufficient printhead pressure); not enough clear space around the barcode.

What to do

1. Follow the Print Wizard, then adjust Darkness or Print Speed in Menu > Print > Print Quality if necessary.
2. Set the printhead pressure to the minimum needed for good quality.
3. Leave at least 3.2 mm (1/8 inch) between the barcode and other printed areas, and between the barcode and the edge of the label.

Source: Printing or print quality problems (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) (official documentation).

Short answer: The installed printhead is not a genuine Zebra printhead, or it is faulty. Install a genuine Zebra printhead; if the error comes back after switching off and on again with a genuine printhead, replace the printhead.

Likely cause

Printhead replaced with one that is not genuine Zebra; printhead fault.

What to do

1. Switch the printer off and on again to see whether the error recurs.
2. If the printhead is not genuine, install a genuine Zebra printhead.
3. If the error comes back with a genuine printhead, replace the printhead.

A flashing red STATUS light indicates a related case: the printer cannot read the printhead's resolution (dpi). The indicator lights page gives no procedure for this case.

Sources: Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Indicator Lights (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: Head Element Out indicates that a printhead element no longer works: Zebra advises replacing the printhead only if this element affects printing. Replace Printhead indicates a printhead at the end of its life, which needs replacing.

Likely cause

Print element out of order (Head Element Out); printhead nearing the end of its service life (Replace Printhead). The print quality table also attributes long unprinted streaks to a damaged element, or to wrinkled ribbon.

What to do

1. First check that the ribbon is not wrinkled (see the ribbon wrinkling entry).
2. If the streaks stay in the same place and affect your barcodes or text, replace the printhead.
3. If the display shows Replace Printhead, plan to replace the printhead.

When to call a technician: for a damaged print element, Zebra's print quality table recommends calling in a service technician.

Sources: Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Printing or print quality problems (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) (official documentation).

Short answer: A solid red NETWORK light indicates an Ethernet or WLAN error: the printer is not connected to the network. On Wi-Fi, solid green means connected with a good signal, flashing green means connected with a weak signal.

Likely cause

Ethernet error or WLAN error.

What to do

1. Read the light's state on Ethernet: off = no link; solid green = 100 Base-T link; solid yellow = 10 Base-T link; solid red = error.
2. On Wi-Fi, at power-up, the light goes from off to flashing red during association, then flashing yellow during authentication. After that: solid green = strong signal, flashing green = weak signal, solid red = error.
3. The System menu also lets you reset the wired or wireless print server: Menu > System > Settings > Restore Defaults, NETWORK option.

Sources: Indicator Lights (opens in a new window) · Indicator Lights (opens in a new window) · System Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: Turn on communication diagnostics mode: the printer then prints every character received in ASCII, with its hexadecimal value underneath. FE, OE, PE or NE codes on the label indicate communication settings that need correcting.

Likely cause

The communication diagnostics test checks the link between the printer and the host computer.

Official procedure (communication diagnostics mode)

1. Set the label width to the actual width of the media or less: Menu > Print > Print Quality > Label Width.
2. Turn on diagnostics mode: Menu > System > Program Language > Diagnostic Mode. Shortcut: hold PAUSE + FEED for 2 seconds in the ready state.
3. Send your data: the printer prints it on a test label, upside down.
4. Read the label: FE = framing error, OE = overrun error, PE = parity error, NE = noise. If any of these codes appears, check the communication settings.
5. Exit diagnostics mode by switching the printer off and on again, or by turning off Diagnostic Mode.

Zebra reminds you to exit this mode after the test so that the printer returns to normal operation.

Sources: Using Communication Diagnostics Mode (opens in a new window) · System Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: The printer only reads USB sticks of 1 TB or less, and some devices need their own power supply. Use a smaller stick, or connect the device to a working power supply.

Likely cause

Stick larger than 1 TB; USB device that requires an external power supply.

What to do

1. Use a USB stick of 1 TB or less.
2. If the device needs an external power supply, connect it to a working power supply.

Source: Miscellaneous Issues (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: The cutter blade has stayed in the media path. Switch off and unplug the printer, then inspect and clean the cutter module following the Zebra procedure.

Likely cause

Cutter blade in the media path.

Caution: The cutter blade is sharp: Zebra asks you not to touch it or rub it with your fingers.

What to do

1. Switch the printer off and unplug it.
2. Inspect the cutter module for debris.
3. Clean it following the “Cleaning and Lubricating the Cutter Module” procedure in the guide.
4. If your ZT231 has the linerless cutter option, refer instead to the “Linerless Printing Issues” section of the guide.

Sources: Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Indicator Lights (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: According to Zebra, the printer driver is not suitable or the application settings are incorrect. Check the driver or software settings and reinstall the driver if necessary.

Likely cause

Incorrect printer driver or unsuitable application settings.

What to do

1. Check the communication and label settings in the driver or software.
2. Reinstall the driver if necessary (“Connecting the Printer to a Device” section of the guide).
3. Check Label Width (Dots) in Menu > Print > Print Quality: too narrow, it truncates the format; too wide, it may print beyond the label.

Sources: Printing or print quality problems (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Print Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: Open Menu > System > Settings > Restore Defaults. PRINTER restores the printer settings other than the network settings, NETWORK resets the wired or wireless print server, LAST SAVED reloads the last saved settings.

Likely cause

The Zebra guide suggests this restore in particular when correctly loaded ribbon is not detected (see Ribbon Out).

What to do

1. Before restoring, print a configuration label to keep a record of the settings: System > Settings > Print: System Settings, or hold FEED + CANCEL for 2 seconds in the ready state.
2. Open Menu > System > Settings > Restore Defaults.
3. Choose PRINTER, NETWORK or LAST SAVED as required.

When to call a technician: if the settings still do not stick after checking the formats and the software, Zebra suggests calling a technician.

If a setting does not stick or changes by itself, the guide states that a firmware setting or a command in a label format may be preventing or resetting it: check your formats and the settings of the software that sends them, or consult the “Programming Guide for ZPL, ZBI, Set-Get-Do, Mirror, and WML” (zebra.com/manuals).

Sources: System Menu (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and Error Messages (opens in a new window) – Zebra ZT231/ZT231R user guide · Alerts and error messages (opens in a new window) – Zebra ZT231/ZT231R user guide (French version) · Miscellaneous Issues (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: During calibration, the printer measured the label length up to the RFID inlay, rather than up to the gap between labels. Set Power Up Action and Head Close Action to FEED, then run a manual calibration.

Likely cause

Label length calibrated on the RFID inlay instead of the gap between labels.

What to do

1. Open Menu > System > Settings.
2. Set Power Up Action and Head Close Action to FEED.
3. Run a manual calibration (see the calibration entry).

Sources: RFID Issues (opens in a new window) · System Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: Zebra first cites missing calibration, labels that are not Gen 2, an incorrect programming position or radio interference. Calibrate manually, check the label type and programming position, and move the printer away from fixed RFID readers.

Likely cause

All labels voided: printer not calibrated for the media; non-Gen 2 labels (only Gen 2 RFID labels are supported); RFID reader cannot be reached; radio interference; labelling software settings overriding the printer's; incorrect programming position; incorrect ZPL or SGD RFID commands. Low yield: labels out of specification (transponder incorrectly placed); unsuitable read and write power levels; interference; outdated printer or reader firmware.

What to do

1. Run a manual calibration (see the calibration entry).
2. Use Gen 2 RFID labels that meet the transponder placement specifications (zebra.com/transponders).
3. Switch off the printer, wait 10 seconds and switch it back on to restore communication with the reader.
4. Move the printer away from fixed RFID readers and other radio sources, and keep the media cover closed during encoding.
5. Align the labelling software settings with those of the printer.
6. Check the RFID programming position in the printer or the software, or restore its default value, and adjust the read and write power levels (RFID Programming Guide 3).
7. Check your label formats (RFID commands) and update the firmware from zebra.com/firmware.

When to call a technician: if the RFID reader still cannot be reached after a restart, Zebra suggests a faulty or poorly connected reader and refers you to technical support or an authorised Zebra RFID technician.

Source: RFID Issues (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: The printer has often been switched back on too quickly for the RFID reader to initialise. Switch it off, wait at least 10 seconds, switch it back on, then check the menus again or print a configuration label.

Likely cause

Restart too quick for the RFID reader to initialise; wrong firmware version; communication with the RFID subsystem impossible. A DATA light that flashes indefinitely after a firmware download (printer or reader) indicates a failed download.

What to do

1. Switch off the printer, wait at least 10 seconds, then switch it back on.
2. Print a configuration label: System > Settings > Print: System Settings, or hold FEED + CANCEL for 2 seconds in the ready state.
3. Check the firmware version (RFID Programming Guide 3) and load the correct version if necessary.
4. After a failed firmware download (DATA flashing endlessly), switch off the printer, wait 10 seconds, switch it back on and restart the download.

When to call a technician: if the RFID subsystem still cannot be reached or the download fails again, Zebra refers you to technical support or an authorised technician.

Sources: RFID Issues (opens in a new window) · System Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: The language setting has been changed from the display or by a firmware command. On the home screen, touch Menu (icon at the bottom left), then the first line: the languages scroll by, each written in its own language.

Likely cause

Language setting changed from the control panel or by a firmware command.

Official procedure

1. On the home screen, touch Menu, the icon at the bottom left.
2. Touch the first option on the screen.
3. Scroll through the languages: each one is shown in its own language.
4. Touch the language you want.
5. Touch the Home icon to return to the home screen.

According to the System menu, this setting (System > Language) changes the language of the home screen, the menus and the error messages.

Sources: Miscellaneous Issues (opens in a new window) · System Menu (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: The ZT231's display can be locked with a control panel password. According to Zebra, this password is not set initially: it has therefore been configured on your printer. The guide refers to the Zebra Link-OS PrintSecure Printer Administration Guide.

Likely cause

Control panel password configured on the printer; its initial value is undefined and must be set before use.

What to do

1. Ask the person who administers your printers.
2. Consult the “Zebra Link-OS PrintSecure Printer Administration Guide” for managing this password.

Source: Miscellaneous Issues (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).

Short answer: Zebra attributes this freeze to an internal electronics or firmware fault. Switch the printer off and on again; if it freezes again, call in a technician. According to the guide, freezing during start-up indicates a main logic board fault.

Likely cause

Internal electronics or firmware fault; freezing at start-up due to a main logic board fault; display needs replacing if characters are missing.

What to do

1. Switch the printer off and on again.
2. If the freeze persists, call in a technician.

When to call a technician: freeze persisting after a restart or characters missing on the display: Zebra refers you to a technician; freezing during start-up is attributed to a main logic board fault.

Source: Miscellaneous Issues (opens in a new window) – Zebra ZT231/ZT231R user guide (official documentation).