Toshiba MMU-P0121H Service Manual page 94

Check code
[dA]
Abnormal overheat of heat sink
Is power supply voltage normal?
YES
Is wiring connector connection
normal on IPDU P.C. board?
YES
Is outdoor fan normal?
YES
Is there screw loose
on the IGBT module or heat sink
on IPDU P.C. board?
NO
Is there blockage of
heat sink cooling duct?
NO
Check IPDU P.C. board.
1. Power supply failure
2. Outdoor fan error
3. Heat sink installation failure
4. Blockage of heat sink cooling duct
5. Defective IPDU P.C. board
NO
NO
NO
YES
YES
3-91
Operation cause
Modify power supply line.
Modify circuit wiring such as
wiring to inverter compressor or
connector connection.
Check fan and fan motor.
Tighten screws.
Remove blockage.