Hitachi WH 14DBDL, Service Manual, Page: 3 / 37

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Symptom Possible cause Troubleshooting Repairing
• Controller failure • Visually check the PCB surface (for
dust, water, and drop-caused
damage).
• Replace the
controller.
• 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 flat cable
(B) connection
failure by dust and
water
• Check the flat cable (B) contact (for
corrosion, water, and other
contaminant).
• Check the switch connector state (for
corro-sion, dust, water, and other
contaminant).
• Replace the DC-
Speed Control
Switch and the
controller.
(3)
No speed-up
(Speed change
disabled)
• Switch contact
failure
• When flat cable (B) is not defective • Replace the DC-
Speed Control
Switch.
(4)
No switching
between High
and Low
• Controller failure • Operate the High/Low selector switch
and confirm its operation.
• Replace the
controller.
(5)
No switching
between Single
and Continuous
• Controller failure • Operate the Single/Continuous
selector switch and confirm its
operation.
• Replace the
controller.
(6)
LED light OFF
• Controller failure • Operate the light switch and confirm
that the LED lights.
• Replace the
controller.