Service Manual

Check SiUS281811E
264 Part 6 Service Diagnosis
5.4 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.
[Point of Measurement and Judgment Criteria]
· Measure the resistance value using a tester at each point of measurement below, 10 minutes later
after power OFF.
To use analog multimeter:
Measurement in the resistance value mode in the range of multiplying 1 k.
To use digital multimeter:
Measurement is executed in the diode check mode.( )
[Preparation]
· Multimeter
 Preparing a multimeter in the analog system is
recommended.
A multimeter in the digital system with diode check
function will be usable.
No.
Point of
Measurement
Judgment
Criteria
Remarks
+–
1P2 U
2 ~ 15 k —2P2 V
3P2 W
4U P2
15 k and
above
(including
)
Due to condenser
charge and so on,
resistance
measurement may
require some time.
5V P2
6W P2
7N3 U
8N3 V
9N3 W
10 U N3
2 ~ 15 k —11 V N3
12 W N3
No.
Point of
Measurement
Judgment
Criteria
Remarks
+–
1P2 U
1.2 V and
over
Due to condenser
charge and so on,
resistance
measurement may
require some time.
2P2 V
3P2 W
4U P2
0.3 ~ 0.7 V —
5V P2
6W P2
7N3 U
8N3 V
9N3 W
10 U N3
1.2 V and
over
Due to condenser
charge and so on,
resistance
measurement may
require some time.
11 V N3
12 W N3