Brother NV4000D Service Manual page 335

Failure Investigation for Electronic Parts Main motor does not turn
Are the resistance values for the
PFSW-S assy. normal?
PFSW-S assy. resistance values
When switch is pressed : 1Ω or less
When switch is not pressed : ∞
Is the NP PCB assembly (D6)
connector correctly connected to
the main PCB assembly (CN15)?
Are the parts on the power PCB
assembly (Q603, Q608, Q611,
Q612, PTC601, PTC602, J117,
and J118) free from discoloration or
flaws?
Is an F01 error message displayed
on the LCD, and was test mode 14
selected after servicing?
From previous page
Is the presser foot lifter down?
Y
Y
Y
N
Y
Replace main PCB assy.
N
Lower the presser foot lifter
N
Replace PFSW-S assy.
N
Reconnect it correctly
Y
Replace the power supply
unit.
*Power supply unit (D6) US: 100V line
EU: 200V line
N
Select test mode 14
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