Problems With Vertical Needle Movement And Reverse Stitching - Baby Lock BLMY Service Manual

Failure Investigation for Electronic Parts Problems with vertical needle movement and reverse stitching
Problems with vertical needle movement
and reverse stitching
When the upper shaft pulley is slowly
turned by hand, does the voltage
between pins 2 & 1, pins 4 &1 and
pins 5 & 1 on the main NF3D PCB
assy. vary 0 – 5 V DC?
5 - 12
Are the resistance values for the
Stop/start switch, reverse switch,
raise needle switch and the thread
cut switch normal?
• Switch resistance values
Switch pressed ...... 1 Ω or less
Switch released ...... ∞
Y
Y
Is the BW switch assy. OFF?
Y
Replace main NF3D PCB assy.
N
Replace SS-VR F2 PCB assy.
N
Replace NP F2 PCB assy.
N
Adjust the assembly of the
BW switch assy.