Samsung AZ09AATEA Service Manual page 37

Troubleshooting
5-2-7 When the 4-way valve is not operated
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 ?(CN72)
(3) Is the 4-way valve connector in good contact?(CN72)
(4) Is the output voltage of the IC01(KA7812) and IC02(KA7805) normal?
(5) Is the unit heating cycle?
Turn off the power, and then turn it on again five
seconds later.
Dose the buzzer sound, when the power ON?
Check whether the "HEAT" LED lamp is on and
the operation starts when pressing the on/off button
of the remocon.
Is the IC03(MAIN PCB) output normal?
- When the 4-way valve is on, IC03.
No. 12 pin Low
Does the relay(RY 74) operate normally?
- When the 4-way valve is operated, the
RY74 should be operated.
Is the 4-way valve coil normal?
Replace the 4-way valve coil.
5-8
Y
N
Y
Y
Y
N
Go to the clause "No power".
• Go to the clause of "when the remocon
dose not operated"
Y
• Normal operation
(Operating the "Heat", relay about 3 min-
utes until the "4-way valve" operates.)
• Check the IC03 for a short and cold
N
soldering.
• Replace the IC03.
• Check the relay coil resistance.
N
(Normal: About 400Ω)
• Replace the relay.
N
• Check the fan motor resistance.
(0Ω : short, ∞Ω : open)
Samsung Electronics