IVT 09LR-N Service Manual page 34

12LRN
2. Troubleshooting of outdoor unit electric components
Check 220-240VAC
input voltage.
NO
Does LED light?
YES
NO
Does LED flash?
YES
Normal
NO
Check 320VDC Short-circuit in DC fan motor
between IPM pins Short-circuit in IPM
(20) and (24) ? Short-circuit in diode bridge
Blown fuse
Defective electrolytic capacitor
Wire disconnection, PWB pattern damage
YES
Short-circuit in PAM IGBT (Q5)
NO
Defective switching power supply circuit
Check switching
Malfunction of 3-terminal regulator IC4, IC1
power supply
Short-circuit in expansion valve coil
output of 12 VDC,
Malfunction of transistor array IC7
15 VDC ?
Solder contact or other problems
YES
NO
Check 5 VDC
Malfunction of 3-terminal regulator IC4, IC1
output ?
YES
Microcomputer oscillator error
Malfunction of microcomputer reset IC
Malfunction of microcomputer
Malfunction of serial signal circuit
Check wiring between indoor and outdoor units.
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