Brother PE-300S Service Manual page 22

67. Screw B and C power unit covers to power supply.
68. Screw on BH switch baseboard (with BH switch assembly and sewing light assembly attached) and attach
sewing light connectors.
69. Attach rear cover to machine with 4 screws.
70. Line plug case up to grooves of rear cover and attach. Use one screw to attach.
71. Adjust backlash of upper and vertical shaft gears. Attach upper shaft gear using 2 screws.
72. While adjusting backlash of upper shaft driving gear, attach idle pulley assembly using 2 screws.
73. Adjust tension of idle pulley and motor pulley belt, and attach main motor assembly with 2 screws. (see page
30 of adjustment procedures)
74. Attach main motor connector to power supply board. Pin down lead wire with clip.
75. Attach set plate C (while attached to NP board) to grooves of rear cover, attach FPM holder using 2 screws.
76. Attach both NP board connectors.
Assembly Points
67. Line up notched section of power unit cover B with rib of power unit cover A and attach. (see diagram A)
69. First insert bobbin winder shaft and handle arm into appropriate hole and groove in rear cover. Then set
presser foot lifter in rear cover, taking care that it does not catch onto bed section of rear cover.
Line up of arm of sewing machine with rib of rear cover (move towards the left of the machine). Fasten
with screws.
71. When doing this, set so that vertical shaft pulley hole is lined up with the top of the needle bar. Adjust
timing of up-down feed. (see page 31 of adjustment procedures)
72. Adjust backlash so that rotation clearance of idle pulley is 0.02-0.5 at the speed shutter and silted section
on the idle pulley when upper shaft driving gear is attached.
75. Turn upper shaft, and attach when needle bar is in its lowermost position (rotation shutter screw should be
facing rear of sewing machine).
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