Printer quality might be degraded by dust or other foreign substance. In this case, clean the printer head as below.

​Clean the printer head.

1)Make sure turn off the printer power prior to cleaning.
2)Printer head gets very hot while printer is running. So turn off the printer and wait approximately 10 minutes before cleaning.
3)While cleaning, make sure not to touch the heated portion of the printer head.

  (Printer head could be damaged by static electricity.)
4)Do not allow the printer head to get scratched or damaged.
5)Clean the printer head using the alcohol moistened cotton swap 
​6)After cleaning the head, wait 1~2 mints until it is completely dried.

Turn off the printer and turn it back on while pressing Feed button.

1)Make sure the battery is fully charged
2)Check the printer cover is completely closed.

Printer quality might be degraded by dust or other foreign substance. In this case, clean the printer head as below.

​Clean the printer head.

1)Make sure turn off the printer power prior to cleaning.
2)Printer head gets very hot while printer is running. So turn off the printer and wait approximately 10 minutes before cleaning.
3)While cleaning, make sure not to touch the heated portion of the printer head.

  (Printer head could be damaged by static electricity.)
4)Do not allow the printer head to get scratched or damaged.
5)Clean the printer head using the alcohol moistened cotton swap 
​6)After cleaning the head, wait 1~2 mints until it is completely dried. 

LK-B11, LK-B21 : Press ‘Pause’ button
       
LK-B30 : Press ‘C’ button
​

1)Black Mark sensor: Adjust black mark sensor to the left/right to match the black mark position at the back of the paper and match the numbers for the paper size.
2)Gap sensor: Adjust the lower part gap sensor and the upper part gap sensor to be positioned the same number.
3)Always, Black mark sensor and Gap sensor must be in the same position
*The initial value of LK-B11, LK-B21 is “0” and LK-B30 is “8”​

Sewoo has their own program called ‘Label Cooker'. 

Label Cooker :
it is an exclusive program to create label and barcode easily, Based on WYSISYG function (print what you see on the screen). With this program, you can create barcode (1D, 2D), text (True type, Device font), line & box and picture (all picture files).
​

​​www.miniprinter.com → Customer Support → Download Center → Refer to the attachment ‘Driver User’s Manual’

1)Check the printer cover is completely closed with closing sound.
2)Check the paper is correctly installed.
(Paper should be comes out from the bottom to the top.)
3)Check the paper.
(Dot Impact and Thermal printer uses different kind of paper. Thermal paper will turn black when you apply heat by a match or lighter, otherwise it is Dot Impact paper. Please check the correct paper is used.)
4)Check the cable connection between POS system and Printer.
5)Check the screw at the interface cable that is well tightened.
6)Run Windows Driver and click “Print Test page”.
7)Check the printer setting through the POS system program.

1)First, check the SMPS(adapter) adapter and the Power connector are connected correctly.
2)Check the SMPS(adapter) and the AC power cord are connected correctly.
3)Check the LED light which is on the SMPS(adapter). (If no lights, SMPS could be out of order)
4)If the printer is still not turned on, contact the service center for replacement or purchase. ​ 

Printer quality might be degraded by dust or other foreign substance. In this case, clean the printer head as below.

​Clean the printer head.

1)Make sure turn off the printer power prior to cleaning.
2)Printer head gets very hot while printer is running. So turn off the printer and wait approximately 10 minutes before cleaning.
3)While cleaning, make sure not to touch the heated portion of the printer head.

  (Printer head could be damaged by static electricity.)
4)Do not allow the printer head to get scratched or damaged.
5)Clean the printer head using the alcohol moistened cotton swap 
​6)After cleaning the head, wait 1~2 mints until it is completely dried. 

You can use the Spill proof cover which covers printer top to prevent damages due to moisture or water.

Clean the printer head.

1)Make sure turn off the printer power prior to cleaning.
2)Printer head gets very hot while printer is running. So turn off the printer and wait approximately 10 minutes before cleaning.
3)While cleaning, make sure not to touch the heated portion of the printer head. (Printer head could be damaged by static electricity.)
4)Do not allow the printer head to get scratched or damaged.
5)Clean the printer head using the alcohol moistened cotton swap 
​6)After cleaning the head, wait 1~2 mints until it is completely dried.

1)Check Dip Switch settings.

2)Perform the printer self test (turn off the printer and turn it back on while pressing Feed button) and check Emulation settings.Check Baud rate and Bit settings. (Applies only with Serial interface)

1)Open the printer cover and check if there are any foreign substances.

​2)Open the cutter cover and use a Phillips Screwdriver and turn left until the cutter blade is in place.

​3)Close the cover and turn the printer on and check printer is working properly.