Brother BAS-311A Service Manual

NO. IN CHAPTER 8
FLOWCHART AND
ERROR STATUS
:f/:6
The presser plate
will not return to
its home position
when the start
foot switch is
stepped on.
#7
The presser plate
shifts to its home
position, then
error code No.3
appears on the
ERROR indicator.
#8
The presser plate
will not shift to
the sewing start
position.
#9
The TEST lamp will
not light when the
TEST switch is
pressed.
#10
No feeding
operation occurs
during the test.
PROBABLE CAUSES
4. PowerPCB
defective
5. Pulse motor or its
cabl~ve
1 fQJ@ 4
©><QJl9
3 [Q) (Q) 6
CHECK I ADJUSTMENT I REPAIR
Refer to #4, 2(a)*.
Unplug connector P4and PS from control
box, then measure the resistance. If it is not
approx. 0.5 n between pins 1 and 2,
between pins 1 and 3, between pins4and 5,
and between pins 4 and 6, the pulse motor
or its cable is defective.
REPLACEMENT
PARTS
Power PCB
Pulse motor
assembly
6. Main circuit board Replace the main circuit board.
Main circuit
board
defective
1. Floppy disk
defective
1. Floppy disk
defective
2. Main circuit board
defective
1. TEST switch or Its
cable defective
A 1 r-, Al3
I I II It 1111111
ld II lllll1llll
Bl
2. Test lamp or its
cable defective
813
AI le ~ Al3
IIIII 1111111
Bl
813
If error code No.3 appears, the floppy disk is
overloaded with sewing programs.
Insert another floppy disk. If the machine Floppy disk
functions normally with the newly inserted
floppy dis~ the old floppy disk Is defective.
Replace the main circuit board. Main drcuit
board
Unplug connector P2 of the control drcult Panel circuit
board, then check the operation panel board
harness connector for continuity. If the
measured value is not both the following
specified values, the panel circuit board is
defective;
Between pins B1 (-)and 810 ( + ): normally
co 0 or the moment the indicator needle
swings when the TEST switch Is on.
Unplug connector P2 of the control circuit
board, then check continuity between pins
A7 ( + ) and A3 (-)of the operation panel
hamess connector. If the tester does not
indicate some value with the maximum
magnified ohm range, the panel circuit
board Is defective.
Panel circuit
board
3. Main circuit board Replace the main circuit board.
Main circuit
board
defective
Refer to #6, Nos.1, 3, 4, 5, and 6 in the
PROBABLE CAUSES column •
-20.
From the library of: Superior Sewing Machine & Supply LLC

Brother BAS-311A Specifications

General

Brand	Brother
Model	BAS-311A
Category	Sewing Machine
Language	English