Brother BAS-342G Service Manual page 143

Problem #20 Thread wiper does not operate.
Cause
1. Incorrect mechanism adjustment
2. Poor connector contact
3. Malfunction of thread
solenoid
4. Malfunction of PMD P.C. board
Problem #21 Needle does not stop in the up position ([E110] or [E111] is displayed.)
Cause
1. Incorrect adjustment
2. Malfunction of synchronizer
3. Malfunction of cord
4. Malfunction of power supply motor
P.C. board
5. Malfunction of main P.C. board
6. Malfunction of motor
Inspection/Remedy/Adjustment
Adjust the thread wiper while referring to "7-11.
Adjusting the thread wiper".
(If it is clear that the thread wiper mechanism is not
operating, carry out inspections 2. and 3. below.)
Check that connector P1 (MAIN) is inserted into
the PMD P.C. board.
wiper Disconnect connector P6 (SOL1) from the PMD
P.C. board, and measure the resistance between
pins 2-5 of the cord-side connector.
OK if approximately 4 Ω
5088Q
With connector P6 (SOL1) connected to the PMD
P.C. board, turn on the power and carry out
sewing, and measure the voltage between pins
2-5 of connector P6 (SOL1).
OK if voltage is output momentarily at the sewing
end.
5089Q
Inspection/Remedy/Adjustment
Adjust while referring to "7-21. Adjusting the
needle up stop home position" and "7-22.
Adjusting the needle up stop position".
Refer to inspection #17.
Refer to inspection #16.
With connector P2 (POWER2) connected to the
PMD P.C. board, measure the voltage at the cord.
OK if approximately 30 V DC between pins 3-4
4892Q
BAS-342G
8. ELECTRICAL MECHANISM
Replacement if a
malfunction
Thread wiper solenoid
PMD P.C. board
Replacement if a
malfunction
Power supply motor P.C.
board
Main P.C. board
Motor
134