Hitachi WH 14DBDL, Service Manual, Page: 2 / 37

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1. Troubleshooting and Repair
Symptom Possible cause Troubleshooting Repairing
• Insufficient
connection of flat
cable (B) of switch
• Check the connection of flat cable (B).
(See [1. Reassembly of the Wiring
Ass'y] on page 5.)
• Securely connect
flat cable (B).
• Switch connector
failure due to dust
or water
• Check flat cable (B) contact (for
corrosion, dust, water, and other
contaminant).
• Check switch connector (for corrosion,
dust, water, and other contaminant).
• Replace the DC-
Speed Control
Switch and the
controller.
High/L
ow
indicat
or
OF
F
• Controller failure
due to dust or
water
• Check the PCB surface (for dust,
water, and other contaminant).
• Replace the
controller.
• Stator FET PCB
failure due to dust,
water, or dropping
• Check the PCB surface (for dust,
water, and drop-caused damage).
• Replace the Stator
FET PCB.
• Controller failure
due to dust, water,
and dropping
• Check the PCB surface (for dust,
water, and drop-caused damage).
• Replace the
controller.
• Poor adhesion of
rotor pinion magnet
• Check whether the magnet is securely
bonded to the rotor pinion.
• Replace the rotor
pinion.
• Insufficient
connection of flat
cable (B) of switch
• Check the connection of flat cable (B).
(See [1. Reassembly of the Wiring
Ass'y] on page 5.)
• Securely connect
flat cable (B).
(1)
No motor
motion
High/L
ow
indicat
or
ON
• Insufficient
connection of
connector cables
(A) and (B)
• Check connection of connector cables
(A) and (B).
(See [1. Reassembly of the Wiring
Ass'y] on page 5.)
• Securely connect
connector cables
(A) and (B).
• Insufficient
connection of
switch flat cable (B)
• Check the flat cable (B) connection.
(See [1. Reassembly of the Wiring
Ass'y] on page 5.)
• Securely connect
flat cable (B).
• Switch connector
failure due to dust
and water
• Check the flat cable (B) contact (for
corrosion, dust, water, and other
contaminant).
• Check the switch connector state (for
corrosion, dust, water, and other
contaminant).
• Replace the DC-
Speed Control
Switch and the
controller.
(2)
No switching
between
Forward and
Reverse
• Switch contact
failure
• When flat cable (B) is not defective • Replace the DC-
Speed Control
Switch.
TROUBLESHOOTING GUIDE