Power Transistor Check - Daikin REYQ-TA Series Service Manual

SiUS371614E
4.4

Power Transistor Check

CHECK 4
Perform the following procedures prior to check.
(1) Power OFF.
(2) Remove all the wiring connected to the PCB where power transistors are mounted on.
Preparation
Multimeter
Point of Measurement and Judgement Criteria
Turn OFF the power supply. Then, after a lapse of 10 minutes or more, make measurement of
resistance.
When using the analog type of multimeter,
make measurement in resistance
measurement mode in the x1 kΩ range.
PCB and Circuit Diagram
J1
J2
J3
Service Diagnosis
Measuring
Judgement
point
No.
Criteria
+ –
1 P2 U
2 P2 V 2 ~ 15 kΩ
3 P2 W
4 U P2
5 V P2
15 kΩ and
6 W P2
more
7 N3 U
(including )
8 N3 V
9 N3 W
10 U N3
11 V N3 2 ~ 15 kΩ
12 W N3
U V
N3
P1 P3
∗ Prepare the analog type of multimeter.
For the digital type of multimeter, those with
diode check function are available for the
checking.
Remarks
Due to condenser
charge and so on,
resistance
measurement may
require some time.
X10A K2
L1
L2
L3
Since the appearance of PCB shown in this outline drawing is different from
the actual appearance, use it as a reference drawing.
W
When using the digital type of multimeter,
make measurement in diode check mode
( )
Measuring
Judgement
point
No.
Criteria
+ –
1 P2 U
1.2 V and
2 P2 V
more
3 P2 W
4 U P2
5 V P2
6 W P2
0.3 ~ 0.7 V
7 N3 U
8 N3 V
9 N3 W
10 U N3
1.2 V and
11 V N3
more
12 W N3
P1 P2 P3
DM
J1
J2
J3
N3
Check
Remarks
Due to condenser
charge and so on,
resistance
measurement may
require some time.
Due to condenser
charge and so on,
resistance
measurement may
require some time.
IGBT
U V W
X11A
278