semiatic

HP LaserJet MFP M139-M142 series lights: what each pattern means

30 light patterns of the HP LaserJet MFP M139-M142 series, from HP’s own guide HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41). Small mono laser multifunction (for example the M140w) with Attention, Ready, Supplies and Wireless lights and a two-character display that alternates Go or Er with a two-digit code.

The lights on this printer

Wi-FiSupplyCodeAttnReady
  • Wireless light (wireless models) — blue
  • Supplies light
  • Display (alternates Go or Er with a two-digit code)
  • Attention light
  • Ready light (in the Power button)

Our own schematic drawing, not HP’s panel layout: the lights are in the order HP’s guide lists them. Where HP does not give a light’s colour, it is drawn filled in the text colour.

  1. Wi-FiSupplyCodeAttnReady

    Ready light on, Attention light off

    Ready light (in the Power button) on; Attention light off. Colour not stated by HP.

    The printer is in Ready mode. The display shows the number of copies currently set.

    HP’s page gives no step for this.

    • The Supplies light may or may not be on as well, depending on the toner level.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  2. Wi-FiSupplyCodeAttnReady

    Ready light on but dim

    Ready light (in the Power button) dimmed; Attention light off. Colour not stated by HP.

    The printer is in Sleep mode.

    HP’s page gives no step for this.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  3. Wi-FiSupplyCodeAttnReady

    Ready light blinking, Attention light off

    Ready light (in the Power button) blinking; Attention light off. Colour not stated by HP.

    The printer is processing a job. For print and scan jobs the display shows the copies setting; for copy jobs, the copy being made; for ID Copy, P1 while the front of the card is scanned and P2 for the back.

    HP’s page gives no step for this.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  4. Wi-FiSupplyCodeAttnReady

    Attention and Ready lights blinking

    Attention light blinking; Ready light (in the Power button) blinking. Colour not stated by HP.

    The printer is initializing, cleaning, or cooling down.

    HP’s page gives no step for this.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  5. Wi-FiSupplyCodeAttnReady

    Supplies light on

    Supplies light on. Colour not stated by HP.

    The toner cartridge is very low and needs replacing.

    HP’s page gives no step for this.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  6. Wi-FiSupplyGo 01CodeAttnReady

    Go 01 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Go 01”. Colour not stated by HP.

    Display code Go/01

    The printer is in manual-feed mode.

    What HP says to do

    1. Load the correct paper type and size into the input tray, then press Start Copy/Resume.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  7. Wi-FiSupplyGo 02CodeAttnReady

    Go 02 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Go 02”. Colour not stated by HP.

    Display code Go/02

    The printer is processing a manual duplex job.

    What HP says to do

    1. Load the pages into the input tray to print their second sides, then press Start Copy/Resume.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  8. Wi-FiSupplyGo 03CodeAttnReady

    Go 03 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Go 03”. Colour not stated by HP.

    Display code Go/03

    The paper type or size of the print job differs from the tray settings.

    What HP says to do

    1. Load the correct paper type and size, or press Start Copy/Resume to carry on with the paper loaded.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  9. Wi-FiSupplyGo 06CodeAttnReady

    Go 06 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Go 06”. Colour not stated by HP.

    Display code Go/06

    A device has asked to connect to the printer with Wi-Fi Direct.

    What HP says to do

    1. Press Start Copy/Resume to connect.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  10. Wi-FiSupplyP2CodeAttnReady

    P2 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “P2”. Colour not stated by HP.

    Display code P2

    An ID Copy job has started and is waiting for the back of the card.

    What HP says to do

    1. Turn the card over and press the ID Copy button to continue.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  11. Wi-FiSupplyEr 01CodeAttnReady

    Er 01 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Er 01”. Colour not stated by HP.

    Display code Er/01

    The input tray is empty.

    What HP says to do

    1. Load the tray.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  12. Wi-FiSupplyEr 02CodeAttnReady

    Er 02 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Er 02”. Colour not stated by HP.

    Display code Er/02

    A door is open.

    What HP says to do

    1. Make sure the top cover is fully closed.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  13. Wi-FiSupplyEr 03CodeAttnReady

    Er 03 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Er 03”. Colour not stated by HP.

    Display code Er/03

    The printer failed to pick up a sheet of paper.

    What HP says to do

    1. Press Start Copy/Resume to continue.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  14. Wi-FiSupplyEr 04CodeAttnReady

    Er 04 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Er 04”. Colour not stated by HP.

    Display code Er/04

    Paper is jammed in the input tray.

    What HP says to do

    1. Clear the jam from the input tray.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  15. Wi-FiSupplyEr 05CodeAttnReady

    Er 05 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Er 05”. Colour not stated by HP.

    Display code Er/05

    Paper is jammed in the toner cartridge area.

    What HP says to do

    1. Clear the jam from inside the printer.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  16. Wi-FiSupplyEr 06CodeAttnReady

    Er 06 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Er 06”. Colour not stated by HP.

    Display code Er/06

    Paper is jammed in the output bin area.

    What HP says to do

    1. Clear the jam from the output area.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  17. Wi-FiSupplyEr 25CodeAttnReady

    Er 25 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Er 25”. Colour not stated by HP.

    Display code Er/25

    The loaded paper is not the size the print job needs.

    What HP says to do

    1. Replace the paper, or press Start Copy/Resume to carry on with the size loaded.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  18. Wi-FiSupplyEr 26CodeAttnReady

    Er 26 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Er 26”. Colour not stated by HP.

    Display code Er/26

    The printer has had a general engine error.

    What HP says to do

    1. Press Start Copy/Resume to continue.
    2. If the error repeats, turn the printer off, wait 30 seconds, and turn it on.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  19. Wi-FiSupplyEr 81CodeAttnReady

    Er 81 with the Attention light blinking

    Attention light blinking; Display (alternates Go or Er with a two-digit code) on; display shows “Er 81”. Colour not stated by HP.

    Display code Er/81

    Incorrect firmware has been loaded.

    What HP says to do

    1. Press Start Copy/Resume to continue, then load the correct firmware.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  20. Wi-FiSupplyEr 08CodeAttnReady

    Er 08 with the Attention light blinking, Ready light on

    Attention light blinking; Ready light (in the Power button) on; Display (alternates Go or Er with a two-digit code) on; display shows “Er 08”. Colour not stated by HP.

    Display code Er/08

    The toner cartridge has reached very low and the printer is set to stop printing at that point.

    What HP says to do

    1. Replace the cartridge, or change its Very Low setting to Continue in the Embedded Web Server. Set to Continue, the Supplies light stays on and no code is shown.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  21. Wi-FiSupplyEr 07CodeAttnReady

    Er 07 with Attention and Supplies lights blinking

    Attention light blinking; Supplies light blinking; Ready light (in the Power button) on; Display (alternates Go or Er with a two-digit code) on; display shows “Er 07”. Colour not stated by HP.

    Display code Er/07

    The toner cartridge is missing or incorrectly installed.

    What HP says to do

    1. Install or reinstall the cartridge.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  22. Wi-FiSupplyEr 11CodeAttnReady

    Er 11 with Attention and Supplies lights blinking

    Attention light blinking; Supplies light blinking; Ready light (in the Power button) on; Display (alternates Go or Er with a two-digit code) on; display shows “Er 11”. Colour not stated by HP.

    Display code Er/11

    There is a problem with the toner cartridge.

    What HP says to do

    1. Make sure the shipping material has been removed from the cartridge and that it is compatible and not damaged.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  23. Wi-FiSupplyEr 14CodeAttnReady

    Er 14 with Attention and Supplies lights blinking

    Attention light blinking; Supplies light blinking; Ready light (in the Power button) on; Display (alternates Go or Er with a two-digit code) on; display shows “Er 14”. Colour not stated by HP.

    Display code Er/14

    The toner cartridge has been protected and is not allowed in this printer.

    What HP says to do

    1. Replace the cartridge.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  24. Wi-FiSupplyEr 17CodeAttnReady

    Er 17 with Attention and Supplies lights blinking

    Attention light blinking; Supplies light blinking; Ready light (in the Power button) on; Display (alternates Go or Er with a two-digit code) on; display shows “Er 17”. Colour not stated by HP.

    Display code Er/17

    An unauthorized toner cartridge is installed. The printer works only with Original HP cartridges.

    What HP says to do

    1. Replace the cartridge.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  25. Wi-FiSupplyEr 30CodeAttnReady

    Er 30 with Attention and Ready lights on

    Attention light on; Ready light (in the Power button) on; Display (alternates Go or Er with a two-digit code) on; display shows “Er 30”. Colour not stated by HP.

    Display code Er/30

    There is a problem with the flatbed scanner.

    What HP says to do

    1. Turn the printer off or unplug the power cord.
    2. Wait 30 seconds, turn it on again, and wait for it to initialize.
    3. If the error persists, contact HP customer support.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  26. Wi-FiSupplyEr 5_CodeAttnReady

    Er 50, 51, 52, 54, 55, 58 or 59 with Attention and Ready lights on

    Attention light on; Ready light (in the Power button) on; Display (alternates Go or Er with a two-digit code) on; display shows “Er 5_”. Colour not stated by HP.

    Display code Er/50, Er/51, Er/52, Er/54, Er/55, Er/58, Er/59

    There is a problem with the print engine.

    What HP says to do

    1. Turn the printer off, wait 30 seconds, and turn it on.
    2. If the error persists, contact HP customer support.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  27. Wi-FiSupplyEr 66CodeAttnReady

    Er 66 with Attention and Ready lights on

    Attention light on; Ready light (in the Power button) on; Display (alternates Go or Er with a two-digit code) on; display shows “Er 66”. Colour not stated by HP.

    Display code Er/66

    There is a problem with the wireless hardware.

    What HP says to do

    1. Press Start Copy/Resume to continue without the wireless hardware.
    2. If the error repeats, turn the printer off, wait 30 seconds, and turn it on.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  28. Wi-FiSupplyEr 7_CodeAttnReady

    Er 74, 76 or 77 with Attention and Ready lights on

    Attention light on; Ready light (in the Power button) on; Display (alternates Go or Er with a two-digit code) on; display shows “Er 7_”. Colour not stated by HP.

    Display code Er/74, Er/76, Er/77

    The printer has had a fatal error it cannot recover from.

    What HP says to do

    1. Turn the printer off, wait 30 seconds, and turn it on.
    2. If the error persists, contact HP customer support.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  29. Wi-FiSupplyEr 75CodeAttnReady

    Er 75 with Attention and Ready lights on

    Attention light on; Ready light (in the Power button) on; Display (alternates Go or Er with a two-digit code) on; display shows “Er 75”. Colour not stated by HP.

    Display code Er/75

    The printer is not connected to the Internet to validate its supply.

    What HP says to do

    1. Reconnect the printer to the Internet so it can validate the cartridge.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

  30. Wi-FiSupplyEr 61CodeAttnReady

    Er 61 with the Wireless light blinking fast

    Wireless light (wireless models) (blue) blinking fast; Display (alternates Go or Er with a two-digit code) on; display shows “Er 61”.

    Display code Er/61

    A wireless WPS connection failed.

    What HP says to do

    1. Press Cancel, then try connecting the printer to the wireless network again.
    2. If the problem persists, connect using the HP Smart app.
    • HP counts this fast blink as 4 blinks every 3 seconds; an ordinary blink on this printer is 2 blinks every 3 seconds.

    Source: HP LaserJet MFP M139-M142 series User Guide — Control panel buttons and lights (pages 3 and 4) and Interpret control-panel light patterns and display codes (pages 38 to 41) (HP), checked 2026-09-29.

Other HP printers

The same light can mean something else on another HP family, so check the model name on your printer.

Sources

HP’s own pages only, read on the date shown. Nothing here comes from third-party “printer codes” sites.