Specifications

SiBE04-624 Troubleshooting
Service Diagnosis 201
2.40 Lights-out of Microcomputer Status Lamp
Remote
Controller Display
—
Outdoor Unit LED
Display
A1 51 ( - )
Method of
Malfunction
Detection
When a microcomputer fault is detected, LED A or LED 5 turns off.
Malfunction
Decision
Conditions
Supposed
Causes

Outdoor unit PCB is not power supplied

Power supply failure due to noise
Troubleshooting
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
(R6021)
Is correct power supplied?
*For the machine with stand-by
power save function, first set the
ON timer using remote
controller to release the stand-
by power save function.
Is LED A turned off?
Is LED 5 turned off?
YES
YES
YES
YES
YES
YES
YES
Dose the LED A flash? Dose the LED 5 flash?
NO
Is voltage
of 5 V applied between
+5V and GND ?
Restart Restart
NO
NO
NO
NO
NO
NO
Is voltage
of 5 V applied between
+5V and GND ?
Turn on power supply.
Turn on breaker.
*Do not work on or touch
components other than
specified part. (Doing so
may cause a short circuit.)
Remove noises.
Replace outdoor unit PCB.
Replace outdoor unit PCB.
Replace outdoor unit PCB.
Remove noises (from the
power supply).
Replace outdoor unit PCB.
Remove noises (from the
power supply).