Hitachi RAM-71QH5 Service Manual page 65

Inspection method 1
Insert the power source, and check to see that the
LED is on.
LED off
Is AC230V flowign to the L/N terminal?
Yes
Is the 25A fuse working normally?
Yes
Is the 5A fuse working normally?
Yes
The control P.W.B. is broken.
Replace the control P.W.B.
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LED on
Follow "Inspecting external electrical parts" and check
the cause of the problem.
No
Connect a commercial-use 220-240V power source
to the L/N terminal.
No
Check to see that varistors 1-3,
diode stacks SPM2 are not
broken.
No
Is varistor 2 broken?
Yes
There is the possibility that an irregular voltage has been
flowing to the L/N terminal. Check to see that the power
source is not abnormality.
Replace the 5A fuse and varistor 2.
– 74 –
Replace the broken part
and the 25A fuse.
No
The control power source is broken.
Replace the control P.W.B.