Baby Lock BLMY Service Manual page 194

Failure Investigation for Electronic Parts Power does not come on
When the power is turned ON, the
buzzer does not sound
With the power cord plugged into an
outlet, is the voltage between pins 1 and
2 on the inlet assy. connector 120 V AC?
Are the voltages between pins 3 & 4,
pins 5 & 4 and pins 6 & 7 of CN14 on
the Main NF3D PCB assy. normal?
• Pins 3 – 4 ... 5 V DC
• Pins 5 – 4 ... 26 V DC
• Pins 6 – 7 ... 26 V DC
Does the buzzer sound when the power
is turned ON with the SS-VR F2 PCB
assy. connector disconnected from the
SS-VR F2 PCB assy.?
Does the buzzer sound when the power
is turned ON with the operation U22
PCB assy. connector disconnected from
the main NF3D PCB assy.?
Y
Y
Y
Y
Replace main NF3D PCB assy.
N
Replace inlet assy.
N
Replace power supply F
N
Replace the SS-VR F2 PCB
assy.
N
Replace operation U22 PCB
assy.
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