Brother b831 Service Manual page 16

(2) Thread Trimmer
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Procedures
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Lever return spring
A \Terminal pin
12-pin plug
o o
o o o
Terminal pin (white)
nal pin
(black)
Remove two screws O snd remove tension release connecting rod O
Remove tension release return spring O.
Turn the machine over.
Remove two ball joint stud screws O 3nd remove connecting rod assembly 0.
Remove two ball joint stud screws O and remove length adjustment connecting bar assembly O.
Loosen screw O and remove pin lever O (shaft and forked lever).
Loosen screw 0 and remove sub lever shaft ®.
Loosen screw with hole ® and remove main lever shaft ®. tension release moving assembly ® (main lever return
spring), and rubber ©.
Remove two flat screws © and remove thread trimmer solenoid ®.
(Remove the pin terminal from the 12-pin plug )
Lower Shaft
Procedures
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Remove timing belt O.
Remove switch mechanism spring O.
Remove screw 0 and remove spring peg O.
Remove flat screw 0 and remove feed bar fork 0 and washer O.
Loosen screw 0 and remove set screw 0.
Loosen two screws 0.
Loosen three screws 0 (right and left)
Loosen screw 0
Loosen screw 0 and two screws 0. and remove timing pulley D ®.
Remove three screws 0 and remove bearing presser 0.
Remove lower shaft 0. (At thistime pinion 0, vertical feed eccentric wheel 0, horizontal eccentric wheel 0, knife
driving cam 0, and spiral gear 0 disconnect.)
* Place pinion 0 and spiral gear 0 in their respective rotating hook positions. (Be sure not to misinsert them.)
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