Brother PC8200 SUPER GALAXIE 2000 Service Manual page 52

18. Bobbin thread detector
does not operate
correctly.
19. Embroidery unit does
not work correctly.
1) Are both ends of bobbin thread detector correctly
positioned?
2) Is voltage between pins 1-2 of connector CN20 (for
bobbin thread detecting LED) approx. 1 VDC?
3) After inserting the bobbin as follows, is voltage
between pins 2-1 of connector CN19(for bobbin thread
detecting photo-diode)correct?
Bobbin without thread...0.1 to 0.2 VDC
Bobbin with thread..............2 to 5 VDC
4) Others
1) Is your card a communication card? Is embroidery unit
connected to sewing machine correctly?
2) Is embroidery unit installed in sewing machine
correctly? Are timing belt tension, gear meshing, and
wiring correct?
3) Are resistances between pins 1-3 and 2-4 of
connectors on X and Y pulse motors (where
embroidery unit is installed) 8-10 W?
4) When ebmbroidery unit is installed, are resistances
between pins 1-3 and 2-4 of connectors CN21 and
CN22 on X and Y pulse motors 8-10 W?.
5) Are resistances between pins 5-6 of connector CN21
on the X pulse motor correct in the following states?
When embroidery unit is installed.....1 W orless
When embroidery unit is removed.....infinite
6) Does a malfunction occur in the initial positioning of
carriage when the power is turned on?
7) Others
-50-
1) Correct directions of bobbin thread
detector ends.
2) Replace photo-diode assembly.
3) Replace photo transistor assembly.
4) Replace main PC board.
1) Check your card and connection
between embroidery unit and
sewing machine.
2) Adjust position of embroidery unit.
(Torque of embroidery frame is
important.)
3) Replace X or Y pulse motor or lead
wire assembly.
4) Replace lead wire assembly or
connector 176496.
5) After confirming the installation of X
pulse motor lead wire assembly,
replace X pulse motor lead wire
assembly, connector 176496, lead
wire assembly or X sensor PC board
assembly.
6) Replace X or Y sensor PC board
assembly.
7) Replace main PC board assembly.