15
VSX-920-K
5
6
7
8
5
6
7
8
A
B
C
D
E
F
CN701 (Pin 1)
Is the voltage
0 to 3.3 V?
No
SUB_ON
Diagnose the MAIN Assy.
Diagnose the MAIN Assy.
Diagnose the MAIN Assy.
Diagnose the MAIN Assy.
Yes
CN701 (Pin 9)
Is the voltage
3.3 V?
Is the voltage
3.3 V?
Is the voltage
3.3 V?
Is the voltage
5 V?
No
SUB MICOM 3.3V
Q711, Q722 (collector)
No
SUB MICOM 3.3V, IC709 3.3V
Yes
Yes
CN702 (Pin 17)
No
HDMI_5V
Yes
CN704 (Pins 3, 4)
No
HDMI_3.3V
Yes
Is
Q711,Q722
base voltage
2.6 V?
No
Yes
To Step 3
Is the voltage
3.3 V?
Is the voltage
1.8 V?
Is the voltage
3.3 V?
Is the voltage
1.2 V?
Replace
IC704.
Replace
IC701.
IC704 (Pin 3)
No
HDMI 3.3V
Yes
IC704 (Pin 2)
No
HDMI 1.8V
Yes
Check the parts and patterns in
the path.
Check the parts and patterns in
the path.
Is IC704
abnormally
hot?
Is IC701
abnormally
hot?
No
Yes
IC701 (Pin 3)
No
HDMI 3.3V
HDMI 1.2V
Yes
The output and GND may be short-circuited.
Check the path between them.
Check the parts and
patterns in the path.
Replace Q711, Q722,
IC706, etc.
Check the parts and
patterns in the path
Q711, Q722, Q714,
Q721, etc.
The output and GND may be short-circuited.
Check the path between them.
Is the voltage
3.3 V?
Is the voltage
1.8 V?
Replace
REG101.
REG101 (Pin 3)
No
HDMI 3.3V
Yes
REG101 (Pin 2)
No
ABT 1V8
Yes
Check the parts and patterns in
the path.
Is REG101
abnormally
hot?
No
Yes
The output and GND may be short-circuited.
Check the path between them.
IC701 (Pin 2)
No
Yes
No
Yes
Step 2: Power supply
Replace
Q714, Q721.
No
Yes
Is
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