2 ] "Machine Error 4F" Error Message; 3 ] Ink-Related Problems - Brother DCP6690CW Service Manual

[ 2 ] "MACHINE ERROR 4F" error message

The error message "MACHINE ERROR 4F" appears if the head drive voltage drops from the
high to low level in an abnormally short period. The source of the problem is mainly the head/
carriage unit.
Check
Head/carriage unit
Main PCB
Carriage PCB

[ 3 ] Ink-related problems

Problems of this nature may arise not only due to machine malfunction but also to the user's
actions.
IMPORTANT: In many cases, the user fails to set ink cartridges in place.
Problems due to the user's actions
Check
Ink cartridges
Problems due to machine malfunction
Check
Head/carriage unit
Maintenance unit
CIS unit
Possible causes
- The carriage-head flat cable is
disconnected from the carriage PCB.
- Piezoelectric ceramic actuator
defective. (Cracks or rare short)
- A power failure when the machine
was in operation resulted in a
damaged part.
- The drive voltage and current supplied
are too low to drive the head/carriage
unit.
- Voltage detection circuit defective.
- Head power circuit insulation failure.
Possible causes
- Ink cartridges are not inserted fully
into the ink refill ASSY.
- One or more of the ink cartridges are
not loaded.
- One or more of the ink cartridges has
run out of ink.
Possible causes
- Air bubbles, high viscosity ink, or
foreign materials have found their
way into the head/carriage unit.
- Head flat cables are broken.
- The carriage-head flat cable has not
been inserted into the carriage PCB.
- Air bubbles, high viscosity ink, or
foreign materials get into the
maintenance unit.
- Torque not transmitted.
- Drain tube bent or pinched.
The CIS unit is weak in identifying
colors.
4-50
Problems that may result
At the start of printing or head
cleaning operation, correct voltage
will not be applied to the
electrodes on the surface of the
piezoelectric ceramic actuator
(described in Chapter 3, Section
3.2.2.1).
The head drive voltage drops from
the high to low level in an
abnormally short period.
The head drive voltage becomes
too high or low.
Problems that may result
The machine will not be able to
print.
Problems that may result
Dot missing occurs on the
printout.
The machine will not be able to
print or drive the head/carriage
unit.
Head cleaning operation will not
be possible and/or the
maintenance unit will not work.
The quality of print colors in
copying operation will be low.
Confidential