Hitachi RAF-35NH5 Service Manual page 294

NSPECT NG EXTERNAL ELECTR CAL PARTS
Check to see that the LED is either on or blinking.
LEDs are divided between those for A cycle and those for B cycle. This is determined by either an A or a B appearing in the
circuit code, for example LD301A or LD301B.
Carry out inspections by examining the on/ blinking status of LEDs 301-304.
LED number LD301
Name Diagnosis
lamp 1
Case 1 Off
Case 2 Blinks once
Case 3 Blinks
Case 4 On
Case 5 Off
(blinks once)
Case 6
Off
Case 7
On
Case 8
Off
Case 9
On
LD302 LD303
Diagnosis Communications
lamp 2 lamp
Off Off
Off Off
Off Off
Blinks Off
Off Blinks
Off Off
Off Off
On Off
On Off
COMPRESSOR
SIDE A.
L L L L
D D D D
3 3 3 3
0 0 0 0
1 2 3 4
A A A A
SERVICE SWITCH
LD304 Status
Operation
lamp
Normal off status or
Off
unconnected
microcomputer power
source
Off Microcomputer reset
status (immediately
after inserting power
source or immediately
after power source
abnormally)
Off
Abnormally stop
Thermistor abnormally
Off
Off (blinks)
Communications error
On
Normal operation
On
OVL1 operation
On
OVL2 operation
On
OVL3 operation
COMPRESSOR
SIDE B.
L L L L
D D D D
3 3 3 3
0 0 0 0
1 2 3 4
B B B B
C1D1 C2D2 C3D3 C4D4
INDOOR 1 INDOOR 2 INDOOR 3 INDOOR 4
- 324 -
Checkpoints
If the LED is not on even when the
power source is
microcomputer
unconnected.
→
Inspection method 1
It is normal for LD301 to blink once
after the power source has been
inserted. If the unit stops when it is in
operation and LD301 blinks once, it is
possible that the power source has
been temporarily
lightening or for some other reason.
Replace the control PCB if this occurs
frequently.
Abnormally stop is shown by the
number of times the LED blinks.
→
Inspection method 2
Thermistor abnormally is shown by
the number of times the LED blinks.
→
Inspection method 3
Communications error is shown
by the number of times the LED
blinks.
→
Inspection method 4
*In the case that an internal unit is
not connected, the number of
connected internal
shown by the number of times
the LED blinks. This is not a
abnormally. The internal unit
has no communications error
and is able to operate normally.
Normal operation
Normal operation
Normal operation
Normal operation
L N
connected, the
power source is
interrupted by
units is