Toshiba RAV-SM304SDT-TR Service Manual page 93

[P12 error]
Turn off the power.
Is there no connection error or
disconnection on connectors CN333
and CN334 of indoor unit P.C. board
(MCC-1570)?
NO
Remove connectors CN333
and CN334 of indoor unit P.C. board
(MCC-1570).
Does the fan rotate without trouble
when handling the fan with hands?
YES
Are resistance values
between phases at fan motor connector
CN333 motor side of indoor P.C. board
(MCC-1570) correct?
∗1
Correct
• Are not coil windings between
• Is not grounded between cabinet and
Is resistance value of
fan motor connector CN334 motor side
of indoor P.C. board
(MCC-1570) correct?
∗2
Correct
Resistance value confirmation of the fan motor position detection circuit
Is not status between
→ The resistance should be approx. 5k to 20kΩ.
Is output of
indoor fan motor position
detection signal correct?
∗3
YES
Confirmation of the fan motor position detection signal
• Using a voltage tester, measure voltage between CN334
• Between
YES
NO
Incorrect
∗1
between (White lead) and
between (Black lead) and
→ The resistance should be the resistance value below.
SM40, SM45, SM56, SM80 → Approx. 70 to 100Ω
SM110, SM140, SM160 → Approx. 27 to 40Ω
Incorrect
∗2
(Yellow lead) and
NO
∗3
(MCC-1570) under condition that CN333 and CN334 are mounted and the power supply is turned on.
→ When rotating the fan slowly with hands, the pin voltage should shake between 0 and 5V.
and : 5V
Correct connection
of connector.
Replace indoor fan motor.
(Red lead) and (White lead),
(Black lead),
(Red lead) opened or shorted?
. → It should be 10MΩ or more.
, ,
(Pink lead) opened or shorted?
– 93 –
CN333
Replace indoor fan motor.
Replace indoor fan motor.
Replace indoor fan motor.
and on the indoor P.C. board
Check indoor P.C. board
(MCC-1570).
Defect → Replace
CN334