PDF file is with installation detailed description and images, which is better for understanding.

R1390 print head installation.pdf

R1390 printer head Installation

Take out the print head
Power off
Press “Online button”,  after the printer head stop moving, press the total power switch, remove the power line
Open the metal cover of the upper part of the printer; there is a small hole (as the show), use Slotted screwdriver to rotate three circles to relax the carriage,and then move the carriage at the middle possition of the machine by hand.
Take out the ink sac one by one (do not spill out the ink on the print head)
Take out the cable clamp on the right side of the carriage
Release the two buckles as the picture showed
Release the three screws on the picture
Take out the printer head carefully.
Pull out the flat cable straightly, do not make damage of the touch spot of the lines.
When the head is out, the metal surface at the bottom of the head can’t contact with anything.
Insert the print head back to the carriage

Insert flat cable
You must make sure the two flat cable did not insert wrong possition
The printer insert back to the carriage straightlly
Tighten the three screws as the picture shown
Insert back the cable clamp on the right side of the carriage
Insert the chip back to the carriage
Insert the ink sac back to the colum
Move the carriage back to the original possition by hand (at the right side of the machine)
Restart your printer
Suction ink from waste ink tube — cleaning automatically by press ink resert botton 7s — Print nozzle check