Brother PR600II Service Manual page 277

Adjustment
1. Enter the test mode, and press [MAIN BOARD TEST] and then press [SENSOR TEST].
Select MAIN BOARD TEST Select MAIN BOARD TEST
2. Rotate the upper shaft counterclockwise until the J-clamp final assembly is lowered19.5 - 20.0 mm from the top
dead center position ( = the needle bar crank rod is in a vertical position).
Top dead center position
3. Loosen the screw securing the encoder base.
Rotate the encoder base counterclockwise until [NEEDLE UP] signal display changes from [H] to [L], and then
tighten the screw.
NOTE • In adjustment the encoder base move counterclockwise and make sure that the encoders do not contact
when tightening the screw.
Screw
NOTE • After adjustment, check the following points and then check the index operation of the needle bar case.
Check points:
• Position of the needle bar clamp and jump bracket when the sewing machine stops operation.
• Position of the thread take-up differential lever when the sewing machine stops operation.
Upper Shaft Encoder Phase Adjustment
Base needle bar
Needle bar crank rod
Thread take-up cam assy
Not contact
Select SENSOR TEST
Secure the encoder base at the
position from [H] to [L]
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