Hitachi RAM-71QH5 Service Manual page 66

Inspection method 2
Check the number of times LD301 blinks.
Yes
LD301: Blinks once
The power source or some other reason may have caused the microcomputer
Reset stop
to reset. Replace the control P.W.B. if the LED blinks once and then stops
frequently during operation.
No
* The LED blinks once after the power source has been inserted.
Yes
LD301: Blinks twice
Is LD302 blinking?
Peak current cut
No
Doesn't blink
Check to see the approximate length of time it takes for the
compressor to stop after switching on and operating two or
three times.
* Wait for three minutes or more before operating.
Takes several minutes to restart.
There is the possibility that the cycly load has become heavy and the
compressor has come loose. Check the compressor.
* In this case the LED may blink three times before stopping.
Yes
LD301: Blinks three times
Check to see the approximate length of time it takes for
Low speed
the compressor to stop after switching on and operating
two or three times.
No
* Wait for three minutes or more before operating.
Takes several minutes
to restart.
There is the chance that the cycle load has become heavy and the
compressor has come loose. Check the compressor.
* In this case the LED may blink twice before stopping.
Yes
LD301: Blinks four times
Switch failure Check to see that the MAIN P.W.B. has 17V.
* Be sure to check the correct points for measuring.
No
abnormally
The power source circuit is broken.
Replace the control P.W.B..
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Doesn't work even after
Blinks twice
the SPM2 is replaced.
The SPM2 is broken.
Replace the SPM2.
Restarts quickly every time.
Restarts quickly
every time.
Ia the wire from the SPM2 to the compressor
loose or broken, or has it been connected
improperly?
O.K. (16-19V)
Ia the wire from the SPM2 to the compressor
loose or broken, or has it been connected
improperly?
If the unit doesn't work even after the SPM2 is replaced, the drive circuit may be broken or
the CN14 cable may be cut. Check to see that an electrical current is flowing through the
CN14 cable.
Cable abnormally
Replace the CN14 cable.
Cable abnormally
No abnormally
Doesn't work
even after the
SPM2 is replaced.
The SPM2 may be broken.
Replace the SPM2.
Cable abnormally
No abnormally
Doesn't work
even after the
SPM2 is replaced.
The SPM2 may be broken.
Replace the SPM2.
No cable abnormally
Replace the MAIN P.W.B..
In the case that one of the compressor cables has become loose (or
broken), the compressor may work even if it is missing a phase. The
compressor occasionally operates in reverse if one of the compressor
cables has been connected improperly. Replace the cable or rewire as
appropriate.
If the unit doesn't work even after replacing the
SPM2, the drive circuit may be broken. Replace
the MAIN P.W.B..
The compressor switch fails if two or more compressor cables are loose (or
broken).
There is the possibility that the compressor will not operate if the compressor
cables have been connected improperly.
Replace the cable or rewire as appropriate.
If the unit doesn't work even after replacing the
SPM2, the position detection circuit may be
broken. Replace the MAIN P.W.B..
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