Brother LK3-B430E Mark II Service Manual page 96

10. ELECTRIC MECHANISM
Error status Probable causes
#15 1. Synchronizer defective
The
machine
cannot
2. Pulse motor is defective or
produce
mechanical adjustment is not
correct
appropriate
stitches.
deviates from what it should
be.
1. Home position sensor not
#16
The thread
adjusted properly
trimmer
does not
operate.
2. Thread trimmer solenoid
defective
3. Main circuit board defective
Thread trimmer
1. Home position sensor not
17
adjusted properly
Thread
take-up
lever does
not
operate.
2. Thread take-up solenoid
defective
89
See #14-1.
a. See #6-4.
b. If stitching deviates because of insufficient
when stitching pressure of the work clamp, see 6-6.
"Adjusting the work clamp lift amount" for
adjustment.
c. Make adjustments if the feed mechanism
has any unnecessary looseness.
Adjust the thread trimmer mechanism (page
24 and 36).
(When it is obvious that the thread trimmer
does not operate, perform the check/repair
/adjust items of #16-2 and #16-3.
Separate P5 (SOL) connectors on the main
circuit
resistance between pins 1 and 2 in the
connector on the cable.
If the resistance is 7 - 8 Ω, the solenoid is not
defective.
With P5 (SOL) connectors plugged in on the
main circuit board, turn on the power,
perform sewing, and measure the voltage
across pins 1 and 2 in the connector on the
cable.
If there is a sudden voltage output at the end
of sewing, it is OK.
Adjust the thread take-up mechanism (page
27).
(If the solenoid does not work even after it is
separated from the mechanical parts, perform
the following items #17-2 and #17-3.)
Separate P4 (SOL2) connectors on the main
circuit
resistance between pins 1 and 2 in the
connector on the cable.
If the resistance is 12 - 14 Ω, the solenoid is
not defective.
LK3-B430E Mark II
Check/repair/adjust
board, and then measure
board, and then measure
Parts to be replaced
Thread trimmer
the solenoid
Main circuit board
the