VSX-AX4AVi-S
194
1
2
3
4
1
2
3
4
C
D
F
A
B
E
7.1.3 TROUBLESHOOTING THE DSP BLOCK
• It is assumed that there is no loose connection or damage in the LCRs.
• Refer to "DSP Block Diagram" and "DSP Assy check point" as the parts marked to in the troubleshooting are located.
Simplified diagnosis
Herein is described how to easily diagnose a defective part in the DSP Assy, only with operations of the main unit.
• Is the DSP Assy a cause of the problem?
Input a digital PCM signal (CD, etc.) and check if the sound is output, by switching AUTO SURR/STREAM DIRECT.
If the sound is output in PURE DIRECT (PCM DIRECT) mode but not in AUTO SURR or DIRECT mode, the DSP Assy
may be defective.
• If the sound is not output when Sound Delay is ON
If the sound is output without a problem when Sound Delay is OFF (0.0 fr) but an abnormality in the sound is detected
when Sound Delay is ON (0.1 - 6.0 fr), it is most likely that SRAM (IC106) or DECODER IC (IC104) in the 1st DSP block
is in failure.
Step 2: Power supply
Step 1: Connections
CN351, CN352
Are the
connectors securely
inserted?
Insert the connectors
securely.
No
CN352 (Pins 24-26)
IC351 (Pin 3)
Is the voltage
5V?
No
5V input
1st Block 3.3V
No
Replace CN352.
Check the output from the
DIGITAL MOTHER Assy.
Yes
Replace IC351.
Yes
Is there
any loose connection
at Pins 24-26 of
CN352?
Is the voltage
3.3V?
No
No
The output and GND may be short-
circuited. Check the path between
them.
Yes
Yes
Is IC351
abnormally hot?
A
Yes
To Step 2
A
A
W
B
IC101 (Pin 7, etc.)
DSP 3.3V
Is the voltage
3.3V?
No
Yes
C
Check the parts and patterns
in the path.
Check the parts and patterns
in the path.
IC102 (Pin 20)
LATCH 1
Is the voltage
3.3V?
No
Yes
D
Check the parts and patterns
in the path.
IC103 (Pin 20)
LATCH 2
Is the voltage
3.3V?
No
Yes
E
Check the parts and patterns
in the path.
IC104 (Pin 8)
Decoder
Is the voltage
3.3V?
No
Yes
F
Check the parts and patterns
in the path.
IC105 (Pin 37)
FLASH ROM
Is the voltage
3.3V?
No
Yes
G
Check the parts and patterns
in the path.
IC106 (Pins 9, 27)
SRAM
Is the voltage
3.3V?
No
Yes
H
Troubleshooting