Brother GTX-4 Service Manual page 101

Flow 1
(1) After replacing the head
circuit boards of white head
and color head, is such failure
cleared?
YES
Heads of non-ink ejection are replaced.
(Electric failure of main unit side)
(2) After checking the wiring of
carriage circuit board through
main circuit board, is such
failure cleared?
OK
NO
Heads of non-ink ejection are not replaced.
(Head failure or maintenance suction failure)
(5) After cleaning the
maintenance parts, is such
failure cleared?
YES
OK
NO
(3) After replacing the
carriage circuit board, is such
failure cleared?
OK
4-4
Improvement of print quality
NO
(6) Is maintenance
operation (suction, exhaust)
conducted correctly?*
YES
Replacement of
maintenance unit
(7) After replacing the suction
cap, is such failure cleared?
YES
OK
NO
(4) Replace the main circuit board
※ Scheduled for incorporation in future versions.
At this time, proceed with the flowchart on the
premise that the suction normally operates (yes).
NO
NO
Head
Replacement