Diagnosis; Diagnosis Flowchart - Pioneer VSX-LX70 Service Manual

5

5. DIAGNOSIS

5.1 DIAGNOSIS FLOWCHART

5.1.1 DSP TROUBLESHOOTING
Unsophisticated Diagnosis
DSP Ass'y malfunction is detected
(The part can be roughly expected just by operation of the main unit.)
• Has DSP Ass'y caused the malfunction?
Inputing a PCM (such as CD) digital signal, check if the sound plays by switching AUTO SURR / STREAM DIRECT.
When the sound doesn't play in AUTO SURROUND or DIRECT MODE though it does in PURE DIRECT (PCM
DIRECT) MODE, DSP Ass'y might be defective.
Troubleshooting
• 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
Step 1: Connections
CN401, CN402
Are the
connectors securely
inserted?
Yes
To Step 2
Step 2: Power supply
A
5V input
CN402 (Pins 24-26)
No
Is the voltage
5V?
Yes
Check the output from the
DIGITAL MOTHER Assy.
B
IC511 (Pin 5) 1st, 2nd Block 3.3V
No
Is the voltage
3.3V?
Yes
The output and GND may be short-
circuited. Check the path between
C them.
IC101 (Pin B3, etc.) 1st DSP 3.3V
No
Check the parts and patterns
Is the voltage
3.3V? in the path.
Yes
5
6
No
Insert the connectors
securely.
Is there
No
any loose connection
at Pins 24-26 of
CN402?
Replace CN402.
Yes
Is IC511 No
abnormally hot?
Replace IC511.
Yes
6
7
A to AF in the troubleshooting are located.
D
LATCH 1
IC161 (Pin 20)
No
Is the voltage
3.3V?
Yes
E
IC162 (Pin 20) LATCH 2
No
Is the voltage
3.3V?
Yes
IC163 (Pin 8) Decoder
No
Is the voltage
3.3V?
Yes
F
IC164 (Pins 12, 37) FLASH ROM
No
Is the voltage
3.3V?
Yes
IC171 (Pins 9, 27) SRAM
No
Is the voltage
3.3V?
Yes
A
VSX-LX70
7
8
Check the parts and patterns
in the path.
Check the parts and patterns
in the path.
Check the parts and patterns
in the path.
Check the parts and patterns
in the path.
Check the parts and patterns
in the path.
8
A
B
C
D
E
F
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