Brother BAS-311E service manual Chapter

Chapter 7

Error status Probable causes Check/repair/adjust Parts to be replaced

Work clamp and presser foot for solenoid specification (BAS-311E)

#4

The work

clamp does

not move

up and

down

when the

foot switch is stepped on.

7. Solenoid is defective.

Work clamp Presser foot

8. Control circuit board is defective.

Work clamp Presser foot

• Remove connector P5 (SOL) on the control circuit		Solenoid
board, and measure the resistance between the		Solenoid code
following pins in the connector on the cord:
Pins 1 and 2 (presser foot): approx. 5-6 Ω.
Pins 3 and 4 (work clamp): approx. 5-6 Ω.
Pins 5 and 6	(thread trimmer): approx. 7-8 Ω.
Pins 7 and 8	(thread wiper): approx. 6-7 Ω.
• Remove connector P5 (SOL) on the control circuit		Control circuit
board, turn on the power, and measure the voltage		board.
across the following pins in the connector on the
control circuit board:
Pins 1 and 2	(presser foot): 0 or +55V
Pins 3 and 4	(work clamp): 0 or +55V

#6

When the

start switch

is stepped

on, the

work clamp

does not

return to its

home

position.

1.	Foot switch and cord are	• Refer to #4-1	Foot switch
	defective.
2.	Any cord in the control box is	• Refer to #4-2	Foot switch code
	defective.		assembly
1.	When the feed mechanism does	• Refer to #4-3	(Quick melting type
	not move and error code [E.A1]		5A-250V)
	appears, fuse has blown.
2.	When the feed mechanism does	• Refer to #4-4.	Power PCB
	not move and error code [E.A1]
	appears, the power PCB is
	defective.

#7

When the

start switch

is stepped

on, an

error code

appears.

3.When the feed mechanism moves in the unusual direction and error code [E.A1] appears, the home position sensor is defective.

• Turn power off and then on again. Move the feed	Home position
mechanism manually around the home position to	sensor
check whether the LED of the home position sensor
is lit.
(The feed mechanism can be moved manually before
the home position is detected.)
• Set the input sensor check mode to check the sensor	Control circuit
input. (Refer to page 90, "7. Checking the input	board
sensor and DIP switch input".) If the above step (a) is
approved, and the sensor input can not be changed,
the cord or the control circuit board is defective.

4.When the feed mechanism operation is unusual, the pulse motor is defective.

P6 (YPM) or P7 (XPM)

•Remove connectors P6 (YPM) and P7 (XPM) on the control circuit board, and measure the resistance between the following pins in the connector on the cord:Pins 1 and 2, pins 2 and 3, pins 3 and 4, pins 4 and 5, and pins 5 and 1.

The resistance in each case should be approx. 2.0 - 2.5 W.

After measurement, return connectors P6 and P7 to their original positions.

Pulse motor Pulse motor harness

108 BAS-311E.311EL.326E.326EL