5-2 Troubleshooting by Symptom
5-2-1 No power
1)Check points
(1)Is the voltage of the power source normal ? (the rating voltage ±10% range.)
(2)Is the electric wire in good contact ?(CN 71, RY 71)
(3)Is the output voltage of the IC01(KA 7812) normal ?(DC 11.5V ~ DC 12.5V)
(4)Is the output voltage of the IC02(KA 7805) normal ?(DC 4.5V ~ DC 5.5V)
Turn off the power, and then turn it on again five
seconds later.
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| Y |
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Dose the buzzer sound, when the power on? |
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| N |
| Y |
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Check whether the "COOLING ICON" LED lamp is |
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on, and the operation starts when pressing the |
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ON/OFF button of the remocon. |
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N
Y
Is the F701(3.15A) fuse blown?
Normal operation.
Normal operation.
Replace the fuse.
N
Is the primary voltage of the transformer normal?
N
(the rating voltage ±10% range.)
Check the power cord and electric wire.
Y
Is the secondary voltage of the transformer normal?
(AC 13V ~ AC 17V)
Y
Is the rectifier diode bridge(BD61) normal?
Y
-Is the voltage of DC 17V ~ DC 23V applied at both ends of the C101 electrolytic condenser?
-Is the voltage of DC 12V applied at both ends of the C102 electrolytic condenser?
-Is the voltage of DC 5V applied at both ends of the C103 electrolytic condenser?
N
N
N
Check and replace the trans.
•Check the BD61 for cold soldering.
•Replace the rectifier diode
•Check both ends of the C101 for short and cold soldering.
•Check the +12V for a short.
•Check the +5V for a short.
•Check and replace the C101~104.
Y
N
Are the IC01(KA7812) or IC02(KA7805) normal?
Y
Replace the assembly main PCB.
•Check the IC01 or IC02 for cold soldering and a short.
•Replace the IC01 or IC02.
FRIEDRICH AIR CONDITIONING CO. |