Brother LK3-B434E MKII Manuel Du Propriétaire

ZE-855A,856A

Wait at least 5 minutes after turning off the power switch and disconnecting the power cord from the wall
outlet before opening the face plate of the control box. Touching areas where high voltages are present can
result in severe injury.

Turn off the power switch and disconnect the power cord before carrying out troubleshooting, otherwise the
machine will operate if the treadle is pressed by mistake, which could result in injury.

If an error code appears in the LED display on the operation panel, check the error code and then turn off the power.
(However, the error display will not disappear immediately when the power is turned off.)
After the panel display turns off, remove the cause of the error and then turn the power back on. (Except for error 

A AAA

)

Needle zigzag position cannot be
found.

Malfunction of home position sensor or harness
Malfunction of zigzag motor or harness
Malfunction of control circuit board

Zigzag motor overcurrent

Zigzag mechanism operation is heavy
Malfunction of zigzag motor or harness
Malfunction of control circuit board

Overheating of control circuit
board heata sink

Malfunction of cooling fan
Blocked air inlet in control box
Malfunction of control circuit board temperature sensor

Exhaust fan problem

Malfunction of right-side fan (when looking from the rear) or har-
ness

Inside air recirculation fan prob-
lem

Malfunction of left-side fan (when looking from the rear)
or harness

Needle zigzag data problem

Malfunction of P-ROM or poor connection
Problem with custom data
Malfunction of control circuit board

Communication problem
between CPUs

Noise affecting transmission
Malfunction of control circuit board or P-ROM version does not match

Machine motor IC problem

Blocked air inlet in control box
Malfunction of machine motor or harness
Malfunction of power supply circuit board

Power supply voltage abnormal-
ity (high)

Power supply voltage is too high

Power supply voltage abnormal-
ity (low)a

Power supply voltage is too low

Machine motor locked

Timing belt is not fitted
Loose pulley
Load too great during sewing
Malfunction of synchronizer or harness
Motor temperature protection function has operated.

(If the motor's serial number is "G03xxxxxx" or later)

Memory element problem

Malfunction of control circuit board

Version mismatch

Mismatch between control circuit board and P-ROM versions