JUKI HZL-UX8 Series - Bobbin Thread Detection Sensor Adjustment (Fine Tuning)

– 39 –
6-23-2 Adjusting the bobbin thread detection sensor
○
AfteryouhavechangedthebobbinthreaddetectionsensorandafteryouhavechangedthemainPCB,carryout
adjustmentofthebobbinthreaddetectionsensor.
 1.Turningthehandwheel,adjustthepositionofthehooktotherangeofangles(147°to162°,or327°to
342°)wherethebobbinthreaddetectionsensorlightpasses.
 2.Placeanemptybobbininthebobbincaseholder.
 3.TurnONthepowertothesewingmachine.Putatestertotheupperrightleadbarandthegroundofthe
VR1 on the main PCB.
  TurningtheVR1withaprecisionscrewdriver,adjustsothatthetesterindicatesthevoltageof"4V".
*
Place the tester in the DC voltage measurement mode.
*
Do not connect the front panel connector when the power is turned on.
Rough indication
of the hook timing
Place an empty bobbin
Put the tester
+ (red) lead bar
Put the tester
- (black) lead bar
Align the bobbin thread
detection sensor 1 with the
notch in the rotating hook
Adjust the VR1
while observing
the voltage
indicated on the
tester
DC voltage
measurement