Please note: It is important that you do not spill distilled water or regular water on the PCB. Use a cotton swab to clean around the PCB.

If you spill any water on the PCB, immediately clean the PCB with isopropyl alcohol.

After cleaning the print-head, allow the device to air dry for a few hours.

In the last picture, you will see 4 black spots in the water. That is hard, dried ink which caused my printing problem.